code: def call_callbacks(self, iid, type, args):
          
          amount = 0
          for tag in self.marker_tags(iid):
              callback = self._tags[tag].get(type, None)
              if callback is not None:
                  amount += 1
                  callback(*args)
          return amount
docs: Call the available callbacks for a certain marker
  
          :param iid: marker identifier
          :type iid: str
          :param type: type of callback (key in tag dictionary)
          :type type: str
          :param args: arguments for the callback
          :type args: tuple
          :return: amount of callbacks called
          :rtype: int