def _convert_split(builder, node, graph, err):
    """
    convert to CoreML Squeeze Layer:
    https://github.com/apple/coremltools/blob/655b3be5cc0d42c3c4fa49f0f0e4a93a26b3e492/mlmodel/format/NeuralNetwork.proto#5003
    """
    axis = node.attrs.get('axis', 0)
    split = node.attrs.get('split', None)
    num_splits = len(node.outputs) if split is None else 2
    builder.add_split_nd(name=node.name, input_name=node.inputs[0],
        output_names=node.outputs, axis=axis, num_splits=num_splits,
        split_sizes=split)
