code: def get_edge(self, src_or_list, dst=None):
          
  
          if isinstance( src_or_list, (list, tuple)) and dst is None:
              edge_points = tuple(src_or_list)
              edge_points_reverse = (edge_points[1], edge_points[0])
          else:
              edge_points = (src_or_list, dst)
              edge_points_reverse = (dst, src_or_list)
  
          match = list()
  
          if edge_points in self.obj_dict['edges'] or (
              self.get_top_graph_type() == 'graph' and
              edge_points_reverse in self.obj_dict['edges']):
  
              edges_obj_dict = self.obj_dict['edges'].get(
                  edge_points,
                  self.obj_dict['edges'].get( edge_points_reverse, None ))
  
              for edge_obj_dict in edges_obj_dict:
                  match.append(
                      Edge(edge_points[0],
                           edge_points[1],
                           obj_dict=edge_obj_dict))
  
          return match
docs: Retrieved an edge from the graph.
  
          Given an edge's source and destination the corresponding
          Edge instance(s) will be returned.
  
          If one or more edges exist with that source and destination
          a list of Edge instances is returned.
          An empty list is returned otherwise.