56     None,  enumerator
80             encoding: Encoding::None,  in default()
97         Self::new_client(inner, Direction::Encode, Encoding::None)  in client_request()
101         Self::new_client(inner, Direction::Decode, Encoding::None)  in client_response()
118             trailers: None,  in new_client()
133             trailers: None,  in new()
147             return Ok(None);  in decode_chunk()
195                     None => {  in poll_decode()
201                             Poll::Ready(None)  in poll_decode()
207             Encoding::None => self  in poll_decode()
245             None => Poll::Ready(None),  in poll_encode()
279                             None => {  in poll_frame()
286                     None => {} // No more data to decode, time to look for trailers  in poll_frame()
311                             Poll::Ready(None)  in poll_frame()
316                         0 => None,  in poll_frame()
326             Direction::Empty => Poll::Ready(None),  in poll_frame()
363             Encoding::None => GRPC_WEB_PROTO,  in to_content_type()
370             _ => Encoding::None,  in from_header()
392         return Ok(None);  in decode_trailers_frame()
517             (GRPC_WEB, Encoding::None),  in encoding_constructors()
518             (GRPC_WEB_PROTO, Encoding::None),  in encoding_constructors()
521             ("foo", Encoding::None),  in encoding_constructors()