The parser which is underlying http\Message.
-## Changelog:
-
-| Version | Change
-|---------|--------
-| 2.2.0 | Added http\Message\Parser API
+> ***NOTE:***
+> This class was added in v2.2.0.
## Constants:
* STATE_BODY_DUMB
Soaking up all input as body.
* STATE_BODY_LENGTH
- Reading body as indicated by `Content-Lenght` or `Content-Range`.
+ Reading body as indicated by `Content-Length` or `Content-Range`.
* STATE_BODY_CHUNKED
Parsing `chunked` encoded body.
* STATE_BODY_DONE
Finished parsing the body.
+* STATE_UPDATE_CL
+ Updating Content-Length based on body size.
* STATE_DONE
Finished parsing the message.