The parser which is underlying http\Header and http\Message.
NOTE:
This class has been added in v2.3.0.
NOTE:
Most of this states won't be returned to the user, because the parser immediately jumps to the next expected state.
Retrieve the current state of the parser.
Parse a string.
int http\Header\Parser::parse(string $data, int $flags, array &$message = NULL)
Parse a stream.
int http\Header\Parser::stream(resource $stream, int $flags, array &$headers)