code: def _assemble_complex(self, stmt):
          
          complex_data, _ = _get_complex_node(stmt.members)
          if complex_data is None:
              logger.info('skip adding complex with no members: %s', stmt.members)
              return
          self.model.add_node_from_data(complex_data)
docs: Example: complex(p(HGNC:MAPK14), p(HGNC:TAB1))