Map MXNet's crop operator attributes to onnx's Crop operator
    and return the created node.

def convert_crop(node, **kwargs):
    """Map MXNet's crop operator attributes to onnx's Crop operator
    and return the created node.
    """
    name, inputs, attrs = get_inputs(node, kwargs)
    num_inputs = len(inputs)

    y, x = list(parse_helper(attrs, "offset", [0, 0]))
    h, w = list(parse_helper(attrs, "h_w", [0, 0]))
    if num_inputs > 1:
        h, w = kwargs["out_shape"][-2:]
    border = [x, y, x + w, y + h]

    crop_node = onnx.helper.make_node(
        "Crop",
        inputs=[inputs[0]],
        outputs=[name],
        border=border,
        scale=[1, 1],
        name=name
    )

    logging.warning(
        "Using an experimental ONNX operator: Crop. " \
        "Its definition can change.")

    return [crop_node]