code: def test_parcels1():
      parcelmap = gimg.get_fdata().astype(np.int32)
      test = np.zeros(parcelmap.shape)
      v = 0
      for i, d in data_generator(test, parcels(parcelmap)):
          v += d.shape[0]
      assert v == np.prod(test.shape)
  
imports: import warnings
  from itertools import chain
  import nibabel
  import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_almost_equal, assert_array_equal
  from ...api import data_generator, parcels, write_data
  from ...reference.coordinate_map import AffineTransform, AxisError
  from ...reference.coordinate_system import CoordinateSystem
  from ..None import image
  from ..image import Image, is_image, iter_axis, rollimg
label_desc: Use image node_id 11 for calling a global function with example usage: test_parcels1() without return types