code: def test_dc_astype():
      def f(a, *, nd):
          a = a.astype(np.int32)
          b = nd.zeros_like(a)
          return [a + b]
  
      _assert_dc(_dc_simple_setup, f)
  
imports: import functools
  import operator
  import numpy
  import mxnet
  import mxnet._deferred_compute
  from mxnet.base import MXNetError
  from mxnet.util import TemporaryDirectory
  import pytest
label_desc: Use image node_id 21 for calling a global function with example usage: test_dc_astype() and returns: list