code: def _is_layer(nn_layer, layer_type):
      """
      :param nn_layer : NN layer proto message
      :param layer_type : str Layer type to check against
      :returns True if nn_layer is of type `layer_type` otherwise False
      """
      return nn_layer.WhichOneof("layer") == layer_type
  
file_path: turicreate/src/external/coremltools_wrap/coremltools/coremltools/converters/mil/backend/nn/passes/mlmodel_passes.py
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  from itertools import permutations
label_desc: Use image node_id 3 for calling a global function with example usage: _is_layer(nn_layer, layer_type) and returns: unknown