code: def isomorphic_to(self, other):
          
          if self.molecule.composition != other.molecule.composition:
              return False
          else:
              self_undir = self.graph.to_undirected()
              other_undir = other.graph.to_undirected()
              nm = iso.categorical_node_match("specie", "ERROR")
              isomorphic = nx.is_isomorphic(self_undir, other_undir, node_match=nm)
              return isomorphic
docs: Checks if the graphs of two MoleculeGraphs are isomorphic to one
          another. In order to prevent problems with misdirected edges, both
          graphs are converted into undirected nx.Graph objects.
  
          :param other: MoleculeGraph object to be compared.
          :return: bool