code: def _handle_command(self, buffer):
          " When text is accepted in the command line. "
          text = buffer.text
  
          # First leave command mode. We want to make sure that the working
          # pane is focused again before executing the command handers.
          self.pymux.leave_command_mode(append_to_history=True)
  
          # Execute command.
          self.pymux.handle_command(textf _handle_command(self, buffer):
          " When text is accepted in the command line. "
          text = buffer.text
  
          # First leave command mode. We want to make sure that the working
          # pane is focused again before executing the command handers.
          self.pymux.leave_command_mode(append_to_history=True)
  
          # Execute command.
          self.pymux.handle_command(text)
docs: When text is accepted in the command line.