code: def _on_return(self, text):
          
          # Ignore if the user hasn't typed a message.
          if not text:
              return
          elif text.startswith('/image') and len(text.split(' ')) == 2:
              # Temporary UI for testing image uploads
              filename = text.split(' ')[1]
              image_file = open(filename, 'rb')
              text = ''
          else:
              image_file = None
          text = replace_emoticons(text)
          segments = hangups.ChatMessageSegment.from_str(text)
          self._coroutine_queue.put(
              self._handle_send_message(
                  self._conversation.send_message(
                      segments, image_file=image_file
                  )
              )
          )
docs: Called when the user presses return on the send message widget.