code: def get_new_edges(self, subject_graph):
          
          result = []
          #print "Match.get_new_edges self.previous_ends1", self.previous_ends1
          for vertex in self.previous_ends1:
              for neighbor in subject_graph.neighbors[vertex]:
                  if neighbor not in self.reverse:
                      result.append((vertex, neighbor))
          return result
docs: Get new edges from the subject graph for the graph search algorithm
  
             The Graph search algorithm extends the matches iteratively by adding
             matching vertices that are one edge further from the starting vertex
             at each iteration.