code: def _receive_eol_token(self):
          
          while self.EOL_TOKEN is None:
              # use yield to have data sent to us - store in buffer
              self._buffer += yield
              if len(self._buffer) > MAX_REQUEST_LENGTH:
                  raise HTTPErrorBadRequest("Max request length exceeded")
              self.EOL_TOKEN = self.determine_newline(self._buffer)
docs: A simple coroutine that is sent data until the first end of line
          (EOL) token is found. This sets the EOL_TOKEN member of the parser
          and pushes all data into the buffer.