code: def target_is_busy(self, target_id=0):
          
          try:
              target = self._target(target_id=target_id)
          except:
              raise NoSuchTargetException()
          return target['state'] == "running"
docs: Returns True or False indicating whether or not the specified
          target is busy.
  
          `target_id` is a target ID (or None for the first target)