code: def create_edge(self, from_doc, to_doc, edge_data={}):
          
  
          return Edge.create(
              collection=self,
              from_doc=from_doc,
              to_doc=to_doc,
              edge_data=edge_data
          )
docs: Creates edge document.
  
              :param from_doc Document from which the edge comes
              :param to_doc Document to which the edge goes
              :param edge_data Extra data for the edge
  
              :returns Document