code: def create_from_ids(self,list_ids):
          
          for this_id in list_ids:
              new_target = Ctarget()
              new_target.set_id(this_id)
              self.node.append(new_target.get_node())
docs: Adds new targets to the span with the specified ids
          @type list_ids: list
          @param list_ids: list of identifiers