code: def test_symbol_copy():
      data = mx.symbol.Variable("data")
      data_2 = copy.deepcopy(data)
      data_3 = copy.copy(data)
      assert data.tojson() == data_2.tojson()
      assert data.tojson() == data_3.tojson()
  
imports: import copy
  import sys
  import os
  import logging
  import re
  import json
  import mxnet
  import numpy
  from common import assertRaises, models, TemporaryDirectory
  from mxnet.base import NotImplementedForSymbol
  from mxnet.test_utils import discard_stderr, rand_shape_nd, use_np, environment
  from mxnet.util import np_shape
  import pickle
label_desc: Use image node_id 4 for calling a global function with example usage: test_symbol_copy() without return types