code: def _merge_points(self, function_address):
          try:
              new_function = self.kb.functions[function_address]
          except KeyError:
              return [ ]
          if function_address not in self._function_merge_points:
              ordered_merge_points = CFGUtils.find_merge_points(function_address, new_function.endpoints,
                                                             new_function.graph)
              self._function_merge_points[function_address] = ordered_merge_points
          return self._function_merge_points[function_address]