version 1.7.2v1.7.2

1 files changed, 1226 insertions, 23 deletions

diff --git a/docs/_build/html/_static/underscore.js b/docs/_build/html/_static/underscore.js
index 5d899143..a12f0d96 100644
--- a/docs/_build/html/_static/underscore.js
+++ b/docs/_build/html/_static/underscore.js
@@ -1,23 +1,1226 @@
-// Underscore.js 0.5.5
-// (c) 2009 Jeremy Ashkenas, DocumentCloud Inc.
-// Underscore is freely distributable under the terms of the MIT license.
-// Portions of Underscore are inspired by or borrowed from Prototype.js,
-// Oliver Steele's Functional, and John Resig's Micro-Templating.
-// For all details and documentation:
-// http://documentcloud.github.com/underscore/
-(function(){var j=this,n=j._,i=function(a){this._wrapped=a},m=typeof StopIteration!=="undefined"?StopIteration:"__break__",b=j._=function(a){return new i(a)};if(typeof exports!=="undefined")exports._=b;var k=Array.prototype.slice,o=Array.prototype.unshift,p=Object.prototype.toString,q=Object.prototype.hasOwnProperty,r=Object.prototype.propertyIsEnumerable;b.VERSION="0.5.5";b.each=function(a,c,d){try{if(a.forEach)a.forEach(c,d);else if(b.isArray(a)||b.isArguments(a))for(var e=0,f=a.length;e<f;e++)c.call(d,
-a[e],e,a);else{var g=b.keys(a);f=g.length;for(e=0;e<f;e++)c.call(d,a[g[e]],g[e],a)}}catch(h){if(h!=m)throw h;}return a};b.map=function(a,c,d){if(a&&b.isFunction(a.map))return a.map(c,d);var e=[];b.each(a,function(f,g,h){e.push(c.call(d,f,g,h))});return e};b.reduce=function(a,c,d,e){if(a&&b.isFunction(a.reduce))return a.reduce(b.bind(d,e),c);b.each(a,function(f,g,h){c=d.call(e,c,f,g,h)});return c};b.reduceRight=function(a,c,d,e){if(a&&b.isFunction(a.reduceRight))return a.reduceRight(b.bind(d,e),c);
-var f=b.clone(b.toArray(a)).reverse();b.each(f,function(g,h){c=d.call(e,c,g,h,a)});return c};b.detect=function(a,c,d){var e;b.each(a,function(f,g,h){if(c.call(d,f,g,h)){e=f;b.breakLoop()}});return e};b.select=function(a,c,d){if(a&&b.isFunction(a.filter))return a.filter(c,d);var e=[];b.each(a,function(f,g,h){c.call(d,f,g,h)&&e.push(f)});return e};b.reject=function(a,c,d){var e=[];b.each(a,function(f,g,h){!c.call(d,f,g,h)&&e.push(f)});return e};b.all=function(a,c,d){c=c||b.identity;if(a&&b.isFunction(a.every))return a.every(c,
-d);var e=true;b.each(a,function(f,g,h){(e=e&&c.call(d,f,g,h))||b.breakLoop()});return e};b.any=function(a,c,d){c=c||b.identity;if(a&&b.isFunction(a.some))return a.some(c,d);var e=false;b.each(a,function(f,g,h){if(e=c.call(d,f,g,h))b.breakLoop()});return e};b.include=function(a,c){if(b.isArray(a))return b.indexOf(a,c)!=-1;var d=false;b.each(a,function(e){if(d=e===c)b.breakLoop()});return d};b.invoke=function(a,c){var d=b.rest(arguments,2);return b.map(a,function(e){return(c?e[c]:e).apply(e,d)})};b.pluck=
-function(a,c){return b.map(a,function(d){return d[c]})};b.max=function(a,c,d){if(!c&&b.isArray(a))return Math.max.apply(Math,a);var e={computed:-Infinity};b.each(a,function(f,g,h){g=c?c.call(d,f,g,h):f;g>=e.computed&&(e={value:f,computed:g})});return e.value};b.min=function(a,c,d){if(!c&&b.isArray(a))return Math.min.apply(Math,a);var e={computed:Infinity};b.each(a,function(f,g,h){g=c?c.call(d,f,g,h):f;g<e.computed&&(e={value:f,computed:g})});return e.value};b.sortBy=function(a,c,d){return b.pluck(b.map(a,
-function(e,f,g){return{value:e,criteria:c.call(d,e,f,g)}}).sort(function(e,f){e=e.criteria;f=f.criteria;return e<f?-1:e>f?1:0}),"value")};b.sortedIndex=function(a,c,d){d=d||b.identity;for(var e=0,f=a.length;e<f;){var g=e+f>>1;d(a[g])<d(c)?(e=g+1):(f=g)}return e};b.toArray=function(a){if(!a)return[];if(a.toArray)return a.toArray();if(b.isArray(a))return a;if(b.isArguments(a))return k.call(a);return b.values(a)};b.size=function(a){return b.toArray(a).length};b.first=function(a,c,d){return c&&!d?k.call(a,
-0,c):a[0]};b.rest=function(a,c,d){return k.call(a,b.isUndefined(c)||d?1:c)};b.last=function(a){return a[a.length-1]};b.compact=function(a){return b.select(a,function(c){return!!c})};b.flatten=function(a){return b.reduce(a,[],function(c,d){if(b.isArray(d))return c.concat(b.flatten(d));c.push(d);return c})};b.without=function(a){var c=b.rest(arguments);return b.select(a,function(d){return!b.include(c,d)})};b.uniq=function(a,c){return b.reduce(a,[],function(d,e,f){if(0==f||(c===true?b.last(d)!=e:!b.include(d,
-e)))d.push(e);return d})};b.intersect=function(a){var c=b.rest(arguments);return b.select(b.uniq(a),function(d){return b.all(c,function(e){return b.indexOf(e,d)>=0})})};b.zip=function(){for(var a=b.toArray(arguments),c=b.max(b.pluck(a,"length")),d=new Array(c),e=0;e<c;e++)d[e]=b.pluck(a,String(e));return d};b.indexOf=function(a,c){if(a.indexOf)return a.indexOf(c);for(var d=0,e=a.length;d<e;d++)if(a[d]===c)return d;return-1};b.lastIndexOf=function(a,c){if(a.lastIndexOf)return a.lastIndexOf(c);for(var d=
-a.length;d--;)if(a[d]===c)return d;return-1};b.range=function(a,c,d){var e=b.toArray(arguments),f=e.length<=1;a=f?0:e[0];c=f?e[0]:e[1];d=e[2]||1;e=Math.ceil((c-a)/d);if(e<=0)return[];e=new Array(e);f=a;for(var g=0;1;f+=d){if((d>0?f-c:c-f)>=0)return e;e[g++]=f}};b.bind=function(a,c){var d=b.rest(arguments,2);return function(){return a.apply(c||j,d.concat(b.toArray(arguments)))}};b.bindAll=function(a){var c=b.rest(arguments);if(c.length==0)c=b.functions(a);b.each(c,function(d){a[d]=b.bind(a[d],a)});
-return a};b.delay=function(a,c){var d=b.rest(arguments,2);return setTimeout(function(){return a.apply(a,d)},c)};b.defer=function(a){return b.delay.apply(b,[a,1].concat(b.rest(arguments)))};b.wrap=function(a,c){return function(){var d=[a].concat(b.toArray(arguments));return c.apply(c,d)}};b.compose=function(){var a=b.toArray(arguments);return function(){for(var c=b.toArray(arguments),d=a.length-1;d>=0;d--)c=[a[d].apply(this,c)];return c[0]}};b.keys=function(a){if(b.isArray(a))return b.range(0,a.length);
-var c=[];for(var d in a)q.call(a,d)&&c.push(d);return c};b.values=function(a){return b.map(a,b.identity)};b.functions=function(a){return b.select(b.keys(a),function(c){return b.isFunction(a[c])}).sort()};b.extend=function(a,c){for(var d in c)a[d]=c[d];return a};b.clone=function(a){if(b.isArray(a))return a.slice(0);return b.extend({},a)};b.tap=function(a,c){c(a);return a};b.isEqual=function(a,c){if(a===c)return true;var d=typeof a;if(d!=typeof c)return false;if(a==c)return true;if(!a&&c||a&&!c)return false;
-if(a.isEqual)return a.isEqual(c);if(b.isDate(a)&&b.isDate(c))return a.getTime()===c.getTime();if(b.isNaN(a)&&b.isNaN(c))return true;if(b.isRegExp(a)&&b.isRegExp(c))return a.source===c.source&&a.global===c.global&&a.ignoreCase===c.ignoreCase&&a.multiline===c.multiline;if(d!=="object")return false;if(a.length&&a.length!==c.length)return false;d=b.keys(a);var e=b.keys(c);if(d.length!=e.length)return false;for(var f in a)if(!b.isEqual(a[f],c[f]))return false;return true};b.isEmpty=function(a){return b.keys(a).length==
-0};b.isElement=function(a){return!!(a&&a.nodeType==1)};b.isArray=function(a){return!!(a&&a.concat&&a.unshift)};b.isArguments=function(a){return a&&b.isNumber(a.length)&&!b.isArray(a)&&!r.call(a,"length")};b.isFunction=function(a){return!!(a&&a.constructor&&a.call&&a.apply)};b.isString=function(a){return!!(a===""||a&&a.charCodeAt&&a.substr)};b.isNumber=function(a){return p.call(a)==="[object Number]"};b.isDate=function(a){return!!(a&&a.getTimezoneOffset&&a.setUTCFullYear)};b.isRegExp=function(a){return!!(a&&
-a.test&&a.exec&&(a.ignoreCase||a.ignoreCase===false))};b.isNaN=function(a){return b.isNumber(a)&&isNaN(a)};b.isNull=function(a){return a===null};b.isUndefined=function(a){return typeof a=="undefined"};b.noConflict=function(){j._=n;return this};b.identity=function(a){return a};b.breakLoop=function(){throw m;};var s=0;b.uniqueId=function(a){var c=s++;return a?a+c:c};b.template=function(a,c){a=new Function("obj","var p=[],print=function(){p.push.apply(p,arguments);};with(obj){p.push('"+a.replace(/[\r\t\n]/g,
-" ").replace(/'(?=[^%]*%>)/g,"\t").split("'").join("\\'").split("\t").join("'").replace(/<%=(.+?)%>/g,"',$1,'").split("<%").join("');").split("%>").join("p.push('")+"');}return p.join('');");return c?a(c):a};b.forEach=b.each;b.foldl=b.inject=b.reduce;b.foldr=b.reduceRight;b.filter=b.select;b.every=b.all;b.some=b.any;b.head=b.first;b.tail=b.rest;b.methods=b.functions;var l=function(a,c){return c?b(a).chain():a};b.each(b.functions(b),function(a){var c=b[a];i.prototype[a]=function(){var d=b.toArray(arguments);
-o.call(d,this._wrapped);return l(c.apply(b,d),this._chain)}});b.each(["pop","push","reverse","shift","sort","splice","unshift"],function(a){var c=Array.prototype[a];i.prototype[a]=function(){c.apply(this._wrapped,arguments);return l(this._wrapped,this._chain)}});b.each(["concat","join","slice"],function(a){var c=Array.prototype[a];i.prototype[a]=function(){return l(c.apply(this._wrapped,arguments),this._chain)}});i.prototype.chain=function(){this._chain=true;return this};i.prototype.value=function(){return this._wrapped}})();
+//     Underscore.js 1.4.4
+//     http://underscorejs.org
+//     (c) 2009-2013 Jeremy Ashkenas, DocumentCloud Inc.
+//     Underscore may be freely distributed under the MIT license.
+
+(function() {
+
+  // Baseline setup
+  // --------------
+
+  // Establish the root object, `window` in the browser, or `global` on the server.
+  var root = this;
+
+  // Save the previous value of the `_` variable.
+  var previousUnderscore = root._;
+
+  // Establish the object that gets returned to break out of a loop iteration.
+  var breaker = {};
+
+  // Save bytes in the minified (but not gzipped) version:
+  var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;
+
+  // Create quick reference variables for speed access to core prototypes.
+  var push             = ArrayProto.push,
+      slice            = ArrayProto.slice,
+      concat           = ArrayProto.concat,
+      toString         = ObjProto.toString,
+      hasOwnProperty   = ObjProto.hasOwnProperty;
+
+  // All **ECMAScript 5** native function implementations that we hope to use
+  // are declared here.
+  var
+    nativeForEach      = ArrayProto.forEach,
+    nativeMap          = ArrayProto.map,
+    nativeReduce       = ArrayProto.reduce,
+    nativeReduceRight  = ArrayProto.reduceRight,
+    nativeFilter       = ArrayProto.filter,
+    nativeEvery        = ArrayProto.every,
+    nativeSome         = ArrayProto.some,
+    nativeIndexOf      = ArrayProto.indexOf,
+    nativeLastIndexOf  = ArrayProto.lastIndexOf,
+    nativeIsArray      = Array.isArray,
+    nativeKeys         = Object.keys,
+    nativeBind         = FuncProto.bind;
+
+  // Create a safe reference to the Underscore object for use below.
+  var _ = function(obj) {
+    if (obj instanceof _) return obj;
+    if (!(this instanceof _)) return new _(obj);
+    this._wrapped = obj;
+  };
+
+  // Export the Underscore object for **Node.js**, with
+  // backwards-compatibility for the old `require()` API. If we're in
+  // the browser, add `_` as a global object via a string identifier,
+  // for Closure Compiler "advanced" mode.
+  if (typeof exports !== 'undefined') {
+    if (typeof module !== 'undefined' && module.exports) {
+      exports = module.exports = _;
+    }
+    exports._ = _;
+  } else {
+    root._ = _;
+  }
+
+  // Current version.
+  _.VERSION = '1.4.4';
+
+  // Collection Functions
+  // --------------------
+
+  // The cornerstone, an `each` implementation, aka `forEach`.
+  // Handles objects with the built-in `forEach`, arrays, and raw objects.
+  // Delegates to **ECMAScript 5**'s native `forEach` if available.
+  var each = _.each = _.forEach = function(obj, iterator, context) {
+    if (obj == null) return;
+    if (nativeForEach && obj.forEach === nativeForEach) {
+      obj.forEach(iterator, context);
+    } else if (obj.length === +obj.length) {
+      for (var i = 0, l = obj.length; i < l; i++) {
+        if (iterator.call(context, obj[i], i, obj) === breaker) return;
+      }
+    } else {
+      for (var key in obj) {
+        if (_.has(obj, key)) {
+          if (iterator.call(context, obj[key], key, obj) === breaker) return;
+        }
+      }
+    }
+  };
+
+  // Return the results of applying the iterator to each element.
+  // Delegates to **ECMAScript 5**'s native `map` if available.
+  _.map = _.collect = function(obj, iterator, context) {
+    var results = [];
+    if (obj == null) return results;
+    if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context);
+    each(obj, function(value, index, list) {
+      results[results.length] = iterator.call(context, value, index, list);
+    });
+    return results;
+  };
+
+  var reduceError = 'Reduce of empty array with no initial value';
+
+  // **Reduce** builds up a single result from a list of values, aka `inject`,
+  // or `foldl`. Delegates to **ECMAScript 5**'s native `reduce` if available.
+  _.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) {
+    var initial = arguments.length > 2;
+    if (obj == null) obj = [];
+    if (nativeReduce && obj.reduce === nativeReduce) {
+      if (context) iterator = _.bind(iterator, context);
+      return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator);
+    }
+    each(obj, function(value, index, list) {
+      if (!initial) {
+        memo = value;
+        initial = true;
+      } else {
+        memo = iterator.call(context, memo, value, index, list);
+      }
+    });
+    if (!initial) throw new TypeError(reduceError);
+    return memo;
+  };
+
+  // The right-associative version of reduce, also known as `foldr`.
+  // Delegates to **ECMAScript 5**'s native `reduceRight` if available.
+  _.reduceRight = _.foldr = function(obj, iterator, memo, context) {
+    var initial = arguments.length > 2;
+    if (obj == null) obj = [];
+    if (nativeReduceRight && obj.reduceRight === nativeReduceRight) {
+      if (context) iterator = _.bind(iterator, context);
+      return initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
+    }
+    var length = obj.length;
+    if (length !== +length) {
+      var keys = _.keys(obj);
+      length = keys.length;
+    }
+    each(obj, function(value, index, list) {
+      index = keys ? keys[--length] : --length;
+      if (!initial) {
+        memo = obj[index];
+        initial = true;
+      } else {
+        memo = iterator.call(context, memo, obj[index], index, list);
+      }
+    });
+    if (!initial) throw new TypeError(reduceError);
+    return memo;
+  };
+
+  // Return the first value which passes a truth test. Aliased as `detect`.
+  _.find = _.detect = function(obj, iterator, context) {
+    var result;
+    any(obj, function(value, index, list) {
+      if (iterator.call(context, value, index, list)) {
+        result = value;
+        return true;
+      }
+    });
+    return result;
+  };
+
+  // Return all the elements that pass a truth test.
+  // Delegates to **ECMAScript 5**'s native `filter` if available.
+  // Aliased as `select`.
+  _.filter = _.select = function(obj, iterator, context) {
+    var results = [];
+    if (obj == null) return results;
+    if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
+    each(obj, function(value, index, list) {
+      if (iterator.call(context, value, index, list)) results[results.length] = value;
+    });
+    return results;
+  };
+
+  // Return all the elements for which a truth test fails.
+  _.reject = function(obj, iterator, context) {
+    return _.filter(obj, function(value, index, list) {
+      return !iterator.call(context, value, index, list);
+    }, context);
+  };
+
+  // Determine whether all of the elements match a truth test.
+  // Delegates to **ECMAScript 5**'s native `every` if available.
+  // Aliased as `all`.
+  _.every = _.all = function(obj, iterator, context) {
+    iterator || (iterator = _.identity);
+    var result = true;
+    if (obj == null) return result;
+    if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context);
+    each(obj, function(value, index, list) {
+      if (!(result = result && iterator.call(context, value, index, list))) return breaker;
+    });
+    return !!result;
+  };
+
+  // Determine if at least one element in the object matches a truth test.
+  // Delegates to **ECMAScript 5**'s native `some` if available.
+  // Aliased as `any`.
+  var any = _.some = _.any = function(obj, iterator, context) {
+    iterator || (iterator = _.identity);
+    var result = false;
+    if (obj == null) return result;
+    if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context);
+    each(obj, function(value, index, list) {
+      if (result || (result = iterator.call(context, value, index, list))) return breaker;
+    });
+    return !!result;
+  };
+
+  // Determine if the array or object contains a given value (using `===`).
+  // Aliased as `include`.
+  _.contains = _.include = function(obj, target) {
+    if (obj == null) return false;
+    if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1;
+    return any(obj, function(value) {
+      return value === target;
+    });
+  };
+
+  // Invoke a method (with arguments) on every item in a collection.
+  _.invoke = function(obj, method) {
+    var args = slice.call(arguments, 2);
+    var isFunc = _.isFunction(method);
+    return _.map(obj, function(value) {
+      return (isFunc ? method : value[method]).apply(value, args);
+    });
+  };
+
+  // Convenience version of a common use case of `map`: fetching a property.
+  _.pluck = function(obj, key) {
+    return _.map(obj, function(value){ return value[key]; });
+  };
+
+  // Convenience version of a common use case of `filter`: selecting only objects
+  // containing specific `key:value` pairs.
+  _.where = function(obj, attrs, first) {
+    if (_.isEmpty(attrs)) return first ? null : [];
+    return _[first ? 'find' : 'filter'](obj, function(value) {
+      for (var key in attrs) {
+        if (attrs[key] !== value[key]) return false;
+      }
+      return true;
+    });
+  };
+
+  // Convenience version of a common use case of `find`: getting the first object
+  // containing specific `key:value` pairs.
+  _.findWhere = function(obj, attrs) {
+    return _.where(obj, attrs, true);
+  };
+
+  // Return the maximum element or (element-based computation).
+  // Can't optimize arrays of integers longer than 65,535 elements.
+  // See: https://bugs.webkit.org/show_bug.cgi?id=80797
+  _.max = function(obj, iterator, context) {
+    if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
+      return Math.max.apply(Math, obj);
+    }
+    if (!iterator && _.isEmpty(obj)) return -Infinity;
+    var result = {computed : -Infinity, value: -Infinity};
+    each(obj, function(value, index, list) {
+      var computed = iterator ? iterator.call(context, value, index, list) : value;
+      computed >= result.computed && (result = {value : value, computed : computed});
+    });
+    return result.value;
+  };
+
+  // Return the minimum element (or element-based computation).
+  _.min = function(obj, iterator, context) {
+    if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
+      return Math.min.apply(Math, obj);
+    }
+    if (!iterator && _.isEmpty(obj)) return Infinity;
+    var result = {computed : Infinity, value: Infinity};
+    each(obj, function(value, index, list) {
+      var computed = iterator ? iterator.call(context, value, index, list) : value;
+      computed < result.computed && (result = {value : value, computed : computed});
+    });
+    return result.value;
+  };
+
+  // Shuffle an array.
+  _.shuffle = function(obj) {
+    var rand;
+    var index = 0;
+    var shuffled = [];
+    each(obj, function(value) {
+      rand = _.random(index++);
+      shuffled[index - 1] = shuffled[rand];
+      shuffled[rand] = value;
+    });
+    return shuffled;
+  };
+
+  // An internal function to generate lookup iterators.
+  var lookupIterator = function(value) {
+    return _.isFunction(value) ? value : function(obj){ return obj[value]; };
+  };
+
+  // Sort the object's values by a criterion produced by an iterator.
+  _.sortBy = function(obj, value, context) {
+    var iterator = lookupIterator(value);
+    return _.pluck(_.map(obj, function(value, index, list) {
+      return {
+        value : value,
+        index : index,
+        criteria : iterator.call(context, value, index, list)
+      };
+    }).sort(function(left, right) {
+      var a = left.criteria;
+      var b = right.criteria;
+      if (a !== b) {
+        if (a > b || a === void 0) return 1;
+        if (a < b || b === void 0) return -1;
+      }
+      return left.index < right.index ? -1 : 1;
+    }), 'value');
+  };
+
+  // An internal function used for aggregate "group by" operations.
+  var group = function(obj, value, context, behavior) {
+    var result = {};
+    var iterator = lookupIterator(value || _.identity);
+    each(obj, function(value, index) {
+      var key = iterator.call(context, value, index, obj);
+      behavior(result, key, value);
+    });
+    return result;
+  };
+
+  // Groups the object's values by a criterion. Pass either a string attribute
+  // to group by, or a function that returns the criterion.
+  _.groupBy = function(obj, value, context) {
+    return group(obj, value, context, function(result, key, value) {
+      (_.has(result, key) ? result[key] : (result[key] = [])).push(value);
+    });
+  };
+
+  // Counts instances of an object that group by a certain criterion. Pass
+  // either a string attribute to count by, or a function that returns the
+  // criterion.
+  _.countBy = function(obj, value, context) {
+    return group(obj, value, context, function(result, key) {
+      if (!_.has(result, key)) result[key] = 0;
+      result[key]++;
+    });
+  };
+
+  // Use a comparator function to figure out the smallest index at which
+  // an object should be inserted so as to maintain order. Uses binary search.
+  _.sortedIndex = function(array, obj, iterator, context) {
+    iterator = iterator == null ? _.identity : lookupIterator(iterator);
+    var value = iterator.call(context, obj);
+    var low = 0, high = array.length;
+    while (low < high) {
+      var mid = (low + high) >>> 1;
+      iterator.call(context, array[mid]) < value ? low = mid + 1 : high = mid;
+    }
+    return low;
+  };
+
+  // Safely convert anything iterable into a real, live array.
+  _.toArray = function(obj) {
+    if (!obj) return [];
+    if (_.isArray(obj)) return slice.call(obj);
+    if (obj.length === +obj.length) return _.map(obj, _.identity);
+    return _.values(obj);
+  };
+
+  // Return the number of elements in an object.
+  _.size = function(obj) {
+    if (obj == null) return 0;
+    return (obj.length === +obj.length) ? obj.length : _.keys(obj).length;
+  };
+
+  // Array Functions
+  // ---------------
+
+  // Get the first element of an array. Passing **n** will return the first N
+  // values in the array. Aliased as `head` and `take`. The **guard** check
+  // allows it to work with `_.map`.
+  _.first = _.head = _.take = function(array, n, guard) {
+    if (array == null) return void 0;
+    return (n != null) && !guard ? slice.call(array, 0, n) : array[0];
+  };
+
+  // Returns everything but the last entry of the array. Especially useful on
+  // the arguments object. Passing **n** will return all the values in
+  // the array, excluding the last N. The **guard** check allows it to work with
+  // `_.map`.
+  _.initial = function(array, n, guard) {
+    return slice.call(array, 0, array.length - ((n == null) || guard ? 1 : n));
+  };
+
+  // Get the last element of an array. Passing **n** will return the last N
+  // values in the array. The **guard** check allows it to work with `_.map`.
+  _.last = function(array, n, guard) {
+    if (array == null) return void 0;
+    if ((n != null) && !guard) {
+      return slice.call(array, Math.max(array.length - n, 0));
+    } else {
+      return array[array.length - 1];
+    }
+  };
+
+  // Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
+  // Especially useful on the arguments object. Passing an **n** will return
+  // the rest N values in the array. The **guard**
+  // check allows it to work with `_.map`.
+  _.rest = _.tail = _.drop = function(array, n, guard) {
+    return slice.call(array, (n == null) || guard ? 1 : n);
+  };
+
+  // Trim out all falsy values from an array.
+  _.compact = function(array) {
+    return _.filter(array, _.identity);
+  };
+
+  // Internal implementation of a recursive `flatten` function.
+  var flatten = function(input, shallow, output) {
+    each(input, function(value) {
+      if (_.isArray(value)) {
+        shallow ? push.apply(output, value) : flatten(value, shallow, output);
+      } else {
+        output.push(value);
+      }
+    });
+    return output;
+  };
+
+  // Return a completely flattened version of an array.
+  _.flatten = function(array, shallow) {
+    return flatten(array, shallow, []);
+  };
+
+  // Return a version of the array that does not contain the specified value(s).
+  _.without = function(array) {
+    return _.difference(array, slice.call(arguments, 1));
+  };
+
+  // Produce a duplicate-free version of the array. If the array has already
+  // been sorted, you have the option of using a faster algorithm.
+  // Aliased as `unique`.
+  _.uniq = _.unique = function(array, isSorted, iterator, context) {
+    if (_.isFunction(isSorted)) {
+      context = iterator;
+      iterator = isSorted;
+      isSorted = false;
+    }
+    var initial = iterator ? _.map(array, iterator, context) : array;
+    var results = [];
+    var seen = [];
+    each(initial, function(value, index) {
+      if (isSorted ? (!index || seen[seen.length - 1] !== value) : !_.contains(seen, value)) {
+        seen.push(value);
+        results.push(array[index]);
+      }
+    });
+    return results;
+  };
+
+  // Produce an array that contains the union: each distinct element from all of
+  // the passed-in arrays.
+  _.union = function() {
+    return _.uniq(concat.apply(ArrayProto, arguments));
+  };
+
+  // Produce an array that contains every item shared between all the
+  // passed-in arrays.
+  _.intersection = function(array) {
+    var rest = slice.call(arguments, 1);
+    return _.filter(_.uniq(array), function(item) {
+      return _.every(rest, function(other) {
+        return _.indexOf(other, item) >= 0;
+      });
+    });
+  };
+
+  // Take the difference between one array and a number of other arrays.
+  // Only the elements present in just the first array will remain.
+  _.difference = function(array) {
+    var rest = concat.apply(ArrayProto, slice.call(arguments, 1));
+    return _.filter(array, function(value){ return !_.contains(rest, value); });
+  };
+
+  // Zip together multiple lists into a single array -- elements that share
+  // an index go together.
+  _.zip = function() {
+    var args = slice.call(arguments);
+    var length = _.max(_.pluck(args, 'length'));
+    var results = new Array(length);
+    for (var i = 0; i < length; i++) {
+      results[i] = _.pluck(args, "" + i);
+    }
+    return results;
+  };
+
+  // Converts lists into objects. Pass either a single array of `[key, value]`
+  // pairs, or two parallel arrays of the same length -- one of keys, and one of
+  // the corresponding values.
+  _.object = function(list, values) {
+    if (list == null) return {};
+    var result = {};
+    for (var i = 0, l = list.length; i < l; i++) {
+      if (values) {
+        result[list[i]] = values[i];
+      } else {
+        result[list[i][0]] = list[i][1];
+      }
+    }
+    return result;
+  };
+
+  // If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**),
+  // we need this function. Return the position of the first occurrence of an
+  // item in an array, or -1 if the item is not included in the array.
+  // Delegates to **ECMAScript 5**'s native `indexOf` if available.
+  // If the array is large and already in sort order, pass `true`
+  // for **isSorted** to use binary search.
+  _.indexOf = function(array, item, isSorted) {
+    if (array == null) return -1;
+    var i = 0, l = array.length;
+    if (isSorted) {
+      if (typeof isSorted == 'number') {
+        i = (isSorted < 0 ? Math.max(0, l + isSorted) : isSorted);
+      } else {
+        i = _.sortedIndex(array, item);
+        return array[i] === item ? i : -1;
+      }
+    }
+    if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item, isSorted);
+    for (; i < l; i++) if (array[i] === item) return i;
+    return -1;
+  };
+
+  // Delegates to **ECMAScript 5**'s native `lastIndexOf` if available.
+  _.lastIndexOf = function(array, item, from) {
+    if (array == null) return -1;
+    var hasIndex = from != null;
+    if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) {
+      return hasIndex ? array.lastIndexOf(item, from) : array.lastIndexOf(item);
+    }
+    var i = (hasIndex ? from : array.length);
+    while (i--) if (array[i] === item) return i;
+    return -1;
+  };
+
+  // Generate an integer Array containing an arithmetic progression. A port of
+  // the native Python `range()` function. See
+  // [the Python documentation](http://docs.python.org/library/functions.html#range).
+  _.range = function(start, stop, step) {
+    if (arguments.length <= 1) {
+      stop = start || 0;
+      start = 0;
+    }
+    step = arguments[2] || 1;
+
+    var len = Math.max(Math.ceil((stop - start) / step), 0);
+    var idx = 0;
+    var range = new Array(len);
+
+    while(idx < len) {
+      range[idx++] = start;
+      start += step;
+    }
+
+    return range;
+  };
+
+  // Function (ahem) Functions
+  // ------------------
+
+  // Create a function bound to a given object (assigning `this`, and arguments,
+  // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if
+  // available.
+  _.bind = function(func, context) {
+    if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
+    var args = slice.call(arguments, 2);
+    return function() {
+      return func.apply(context, args.concat(slice.call(arguments)));
+    };
+  };
+
+  // Partially apply a function by creating a version that has had some of its
+  // arguments pre-filled, without changing its dynamic `this` context.
+  _.partial = function(func) {
+    var args = slice.call(arguments, 1);
+    return function() {
+      return func.apply(this, args.concat(slice.call(arguments)));
+    };
+  };
+
+  // Bind all of an object's methods to that object. Useful for ensuring that
+  // all callbacks defined on an object belong to it.
+  _.bindAll = function(obj) {
+    var funcs = slice.call(arguments, 1);
+    if (funcs.length === 0) funcs = _.functions(obj);
+    each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
+    return obj;
+  };
+
+  // Memoize an expensive function by storing its results.
+  _.memoize = function(func, hasher) {
+    var memo = {};
+    hasher || (hasher = _.identity);
+    return function() {
+      var key = hasher.apply(this, arguments);
+      return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments));
+    };
+  };
+
+  // Delays a function for the given number of milliseconds, and then calls
+  // it with the arguments supplied.
+  _.delay = function(func, wait) {
+    var args = slice.call(arguments, 2);
+    return setTimeout(function(){ return func.apply(null, args); }, wait);
+  };
+
+  // Defers a function, scheduling it to run after the current call stack has
+  // cleared.
+  _.defer = function(func) {
+    return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1)));
+  };
+
+  // Returns a function, that, when invoked, will only be triggered at most once
+  // during a given window of time.
+  _.throttle = function(func, wait) {
+    var context, args, timeout, result;
+    var previous = 0;
+    var later = function() {
+      previous = new Date;
+      timeout = null;
+      result = func.apply(context, args);
+    };
+    return function() {
+      var now = new Date;
+      var remaining = wait - (now - previous);
+      context = this;
+      args = arguments;
+      if (remaining <= 0) {
+        clearTimeout(timeout);
+        timeout = null;
+        previous = now;
+        result = func.apply(context, args);
+      } else if (!timeout) {
+        timeout = setTimeout(later, remaining);
+      }
+      return result;
+    };
+  };
+
+  // Returns a function, that, as long as it continues to be invoked, will not
+  // be triggered. The function will be called after it stops being called for
+  // N milliseconds. If `immediate` is passed, trigger the function on the
+  // leading edge, instead of the trailing.
+  _.debounce = function(func, wait, immediate) {
+    var timeout, result;
+    return function() {
+      var context = this, args = arguments;
+      var later = function() {
+        timeout = null;
+        if (!immediate) result = func.apply(context, args);
+      };
+      var callNow = immediate && !timeout;
+      clearTimeout(timeout);
+      timeout = setTimeout(later, wait);
+      if (callNow) result = func.apply(context, args);
+      return result;
+    };
+  };
+
+  // Returns a function that will be executed at most one time, no matter how
+  // often you call it. Useful for lazy initialization.
+  _.once = function(func) {
+    var ran = false, memo;
+    return function() {
+      if (ran) return memo;
+      ran = true;
+      memo = func.apply(this, arguments);
+      func = null;
+      return memo;
+    };
+  };
+
+  // Returns the first function passed as an argument to the second,
+  // allowing you to adjust arguments, run code before and after, and
+  // conditionally execute the original function.
+  _.wrap = function(func, wrapper) {
+    return function() {
+      var args = [func];
+      push.apply(args, arguments);
+      return wrapper.apply(this, args);
+    };
+  };
+
+  // Returns a function that is the composition of a list of functions, each
+  // consuming the return value of the function that follows.
+  _.compose = function() {
+    var funcs = arguments;
+    return function() {
+      var args = arguments;
+      for (var i = funcs.length - 1; i >= 0; i--) {
+        args = [funcs[i].apply(this, args)];
+      }
+      return args[0];
+    };
+  };
+
+  // Returns a function that will only be executed after being called N times.
+  _.after = function(times, func) {
+    if (times <= 0) return func();
+    return function() {
+      if (--times < 1) {
+        return func.apply(this, arguments);
+      }
+    };
+  };
+
+  // Object Functions
+  // ----------------
+
+  // Retrieve the names of an object's properties.
+  // Delegates to **ECMAScript 5**'s native `Object.keys`
+  _.keys = nativeKeys || function(obj) {
+    if (obj !== Object(obj)) throw new TypeError('Invalid object');
+    var keys = [];
+    for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key;
+    return keys;
+  };
+
+  // Retrieve the values of an object's properties.
+  _.values = function(obj) {
+    var values = [];
+    for (var key in obj) if (_.has(obj, key)) values.push(obj[key]);
+    return values;
+  };
+
+  // Convert an object into a list of `[key, value]` pairs.
+  _.pairs = function(obj) {
+    var pairs = [];
+    for (var key in obj) if (_.has(obj, key)) pairs.push([key, obj[key]]);
+    return pairs;
+  };
+
+  // Invert the keys and values of an object. The values must be serializable.
+  _.invert = function(obj) {
+    var result = {};
+