code: def test_pull():
      """test pull"""
  
      def check_pull(kv):
          a = mx.nd.ones(shape)
          b = mx.nd.zeros(shape)
          kv.init("1", mx.nd.zeros(shape))
          kv.push("1", [a, a, a, a])
          kv.pull("1", b)
          check_diff_to_scalar(b, 4)
          kv.init("2", mx.nd.zeros(shape))
          kv.pull("2", b)
          check_diff_to_scalar(b, 0)
  
      check_pull(mx.kv.create("device"))
      check_pull(mx.kv.create())
  
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 7 for calling a global function with example usage: test_pull() without return types