Some messages with a fair amount of recursion.  These messages were
created by sequoia.  See serialize/serialize.rs:serialize_and_parse_1.

recursive-1.gpg:

  1: CompressedData(CompressedData { algo: 0 })
   1: Literal(Literal { body: "one (3 bytes)" })
   2: Literal(Literal { body: "two (3 bytes)" })
  2: Literal(Literal { body: "three (5 bytes)" })

recursive-2.gpg:

  1: CompressedData(CompressedData { algo: 0 })
   1: CompressedData(CompressedData { algo: 0 })
    1: Literal(Literal { body: "one (3 bytes)" })
    2: Literal(Literal { body: "two (3 bytes)" })
   2: CompressedData(CompressedData { algo: 0 })
    1: Literal(Literal { body: "three (5 bytes)" })
    2: Literal(Literal { body: "four (4 bytes)" })

recursive-3.gpg:

  1: CompressedData(CompressedData { algo: 0 })
   1: CompressedData(CompressedData { algo: 0 })
    1: CompressedData(CompressedData { algo: 0 })
     1: CompressedData(CompressedData { algo: 0 })
      1: Literal(Literal { body: "one (3 bytes)" })
      2: Literal(Literal { body: "two (3 bytes)" })
   2: CompressedData(CompressedData { algo: 0 })
    1: CompressedData(CompressedData { algo: 0 })
     1: Literal(Literal { body: "three (5 bytes)" })
    2: Literal(Literal { body: "four (4 bytes)" })

recursive-4.gpg:

  1: CompressedData(CompressedData { algo: 0 })
   1: Literal(Literal { body: "one (3 bytes)" })
   2: Literal(Literal { body: "two (3 bytes)" })
  2: Literal(Literal { body: "three (5 bytes)" })
  3: Literal(Literal { body: "four (4 bytes)" })
  4: CompressedData(CompressedData { algo: 0 })
   1: Literal(Literal { body: "five (4 bytes)" })
   2: Literal(Literal { body: "six (3 bytes)" })