code: def convert_square(node, **kwargs):
      
      name, input_nodes, _ = get_inputs(node, kwargs)
  
      initializer = kwargs["initializer"]
      data_type = onnx.mapping.NP_TYPE_TO_TENSOR_TYPE[np.dtype('int64')]
  
      power2_name = "square_tensor" + str(kwargs["idx"])
      tensor_node = onnx.helper.make_tensor_value_info(power2_name, data_type, (1,))
      initializer.append(
          onnx.helper.make_tensor(
              name=power2_name,
              data_type=data_type,
              dims=(1,),
              vals=[2],
              raw=False,
          )
      )
  
      input_nodes.append(power2_name)
  
      node = onnx.helper.make_node(
          "Pow",
          input_nodes,
          [name],
          name=name
      )
      return [tensor_node, node]
docs: Map MXNet's square operator attributes to onnx's Pow operator
      and return the created node.