153                 return Ok(None);  in decode_chunk()
210                 return Ok(None);  in decode_chunk()
241             return Ok(Some(decode_buf));  in decode_chunk()
244         Ok(None)  in decode_chunk()
250             Some(Ok(frame)) => frame,  in poll_frame()
253                     return Poll::Ready(Ok(None));  in poll_frame()
266                     Ok(None)  in poll_frame()
273             Ok(Some(()))  in poll_frame()
281             Ok(None)  in poll_frame()
296         Ok(())  in response()
331             Some(Ok(m)) => Ok(Some(m)),  in message()
333             None => Ok(None),  in message()
356             return Ok(Some(MetadataMap::from_headers(trailers)));  in trailers()
365             return Ok(Some(MetadataMap::from_headers(trailers)));  in trailers()
369         Ok(None)  in trailers()
377                     Ok(Some(msg))  in decode_chunk()
379                 None => Ok(None),  in decode_chunk()
381             None => Ok(None),  in decode_chunk()
399                 return Poll::Ready(Some(Ok(item)));  in poll_next()
408             Ok(()) => None,  in poll_next()