code: def _assemble_modification(self, stmt):
          
          sub_agent = deepcopy(stmt.sub)
          sub_agent.mods.append(stmt._get_mod_condition())
          activates = isinstance(stmt, AddModification)
          relation = get_causal_edge(stmt, activates)
          self._add_nodes_edges(stmt.enz, sub_agent, relation, stmt.evidence)
docs: Example: p(HGNC:MAP2K1) => p(HGNC:MAPK1, pmod(Ph, Thr, 185))