code: def test_symbol_children():
      data = mx.symbol.Variable("data")
      oldfc = mx.symbol.FullyConnected(
          data=data, name="fc1", num_hidden=10
      )
      net1 = mx.symbol.FullyConnected(
          data=oldfc, name="fc2", num_hidden=100
      )
  
      assert net1.get_children().list_outputs() == [
          "fc1_output",
          "fc2_weight",
          "fc2_bias",
      ]
      assert len(net1.get_children()) == 3
      assert net1.get_children().get_children().list_outputs() == [
          "data",
          "fc1_weight",
          "fc1_bias",
      ]
      assert len(net1.get_children().get_children()) == 3
      assert net1.get_children()["fc2_weight"].list_arguments() == [
          "fc2_weight"
      ]
      assert net1.get_children()["fc2_weight"].get_children() is None
  
      data = mx.sym.Variable("data")
      sliced = mx.sym.SliceChannel(data, num_outputs=3, name="slice")
      concat = mx.sym.Concat(*list(sliced))
  
      assert concat.get_children().list_outputs() == [
          "slice_output0",
          "slice_output1",
          "slice_output2",
      ]
      assert sliced.get_children().list_outputs() == ["data"]
  
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 6 for calling a global function with example usage: test_symbol_children() without return types