code: def _make_output_layers(self):
      for name, layer in self.layer_map.items():
          if len(layer.out_edges) == 0:
              self.output_layers.append(name)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
label_desc: Use image node_id 5 for calling the Graph obj's underlying member method code with example usage: obj._make_output_layers() without return types