code: def _remove_layer(self, layer):
          
          successors = self.get_successors(layer)
          predecessors = self.get_predecessors(layer)
          # remove all edges
          for succ in successors:
              self._remove_edge(layer, succ)
          for pred in predecessors:
              self._remove_edge(pred, layer)
          # remove layer in the data structures
          self.keras_layer_map.pop(layer)
          self.layer_list.remove(layer)
docs: remove the layer and its input/output edges