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

def convert_lrn(node, **kwargs):
    """Map MXNet's LRN operator attributes to onnx's LRN operator
    and return the created node.
    """
    name, input_nodes, attrs = get_inputs(node, kwargs)

    alpha = float(attrs.get("alpha", 0.0001))
    beta = float(attrs.get("beta", 0.75))
    bias = float(attrs.get("knorm", 1.0))
    size = int(attrs.get("nsize"))

    lrn_node = onnx.helper.make_node(
        "LRN",
        inputs=input_nodes,
        outputs=[name],
        name=name,
        alpha=alpha,
        beta=beta,
        bias=bias,
        size=size
    )

    return [lrn_node]