code: def target_exists(self, target_id=0):
          
          try:
              target = self._target(target_id=target_id)
          except Exception as e:
              log.error("Exception checking if target exists: {} {}".format(type(e), e))
              return False
          return target is not None
docs: Returns True or False indicating whether or not the specified
          target is present and valid.
  
          `target_id` is a target ID (or None for the first target)