code: def _get_network_output(spec):
      """
      :param spec : CoreML Specification
      :returns network output names
      """
      network_output_names = []
      for _out in spec.description.output:
          network_output_names.append(_out.name)
      return network_output_names
  
file_path: coremltools/coremltools/converters/mil/backend/nn/passes/mlmodel_passes.py
label_desc: Use image node_id 6 for calling a global function with example usage: _get_network_output(spec) and returns: network_output_names