code: def send_command(self, command):
          
          if self._pipe_commands:
              self._pipe_commands.send(command)
          else:
              if self.shutdown:
                  # Stop delivering messages in shutdown.
                  self.log.info(
                      "During shutdown no command queue pipe found for command\n%s",
                      str(command),
                  )
              else:
                  self.log.error(
                      "No command queue pipe found for command\n%s", str(command)
                  )
docs: Send command to service via the command queue.