code: def test_list_kv_pair():
      """list key-value pair push & pull"""
  
      def check_list_kv_pair(kv, key, stype):
          kv.push(
              key, [mx.nd.ones(shape).tostype(stype) * 4] * len(key)
          )
          val = [mx.nd.empty(shape)] * len(key)
          kv.pull(key, out=val)
          for v in val:
              check_diff_to_scalar(v, 4)
  
      stypes = ["default", "row_sparse"]
      for stype in stypes:
          check_list_kv_pair(init_kv(), keys, stype)
          check_list_kv_pair(init_kv_with_str(), str_keys, stype)
  
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
  import pytest
label_desc: Use image node_id 8 for calling a global function with example usage: test_list_kv_pair() without return types