code: def remove_nodes(self, indices):
          
  
          self.molecule.remove_sites(indices)
          self.graph.remove_nodes_from(indices)
  
          mapping = {}
          for correct, current in enumerate(sorted(self.graph.nodes)):
              mapping[current] = correct
  
          nx.relabel_nodes(self.graph, mapping, copy=False)
          self.set_node_attributes()
docs: A wrapper for Molecule.remove_sites().
  
          :param indices: list of indices in the current Molecule (and graph) to
              be removed.
          :return: