TODO
[ ] tokens
  [ ] TOKEN_CONNECTION_START
  [ ] TOKEN_CONNECTION_END
  [ ] TOKEN_REQUEST_START
[ ] content-types:
  [ ] x-form-url-encoded
  [ ] multipart/form-data
      https://tools.ietf.org/html/rfc7578
[ ] transfer-encodings
  [-] chunked
  [ ] gzip
  [ ] deflate
  [ ] compress