code: def cliques(self, xg):
          
          g = nx.DiGraph()
          for (x,y) in self.merged_ontology.get_graph().edges():
              g.add_edge(x,y)
          for (x,y) in xg.edges():
              g.add_edge(x,y)
              g.add_edge(y,x)
          return list(strongly_connected_components(g))
docs: Return all equivalence set cliques, assuming each edge in the xref graph is treated as equivalent,
          and all edges in ontology are subClassOf
  
          Arguments
          ---------
          xg : Graph
              an xref graph
  
          Returns
          -------
          list of sets