code: def test_custom_store():
      kv = mx.kv.create("teststore")
      out = mx.nd.empty((1,))
      kv.broadcast(1, mx.nd.ones((1,)), out=out)
      check_diff_to_scalar(out, 1)
      assert type(kv).is_capable("optimizer") == False
      kv.broadcast(1, mx.nd.ones((1,)), out=out)
      check_diff_to_scalar(out, 1)
      arr_list = [mx.nd.empty((1,))] * 2
      kv.pushpull(1, [mx.nd.ones((1,))] * 2, out=arr_list)
      for arr in arr_list:
          check_diff_to_scalar(arr, 2)
      kv.pushpull(1, arr_list)
      for arr in arr_list:
          check_diff_to_scalar(arr, 4)
  
file_path: mxnet/tests/python/unittest/test_kvstore_custom.py
imports: import mxnet
  import numpy
  import unittest
  from mxnet.test_utils import rand_ndarray, assert_almost_equal
  from common import assertRaises
  from mxnet.base import py_str, MXNetError
label_desc: Use image node_id 7 for calling a global function with example usage: test_custom_store() without return types