code: def make_data_int16(dx=100, dy=100, dz=50):
      return (
          256 * (np.random.rand(dx, dy, dz) - np.random.rand())
      ).astype("int16")
  
imports: import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from ....core.image.image_spaces import make_xyz_image
  from ....testing import assert_almost_equal
  from .._registration import _joint_histogram
  from ..affine import Affine, Rigid
  from ..histogram_registration import HistogramRegistration
label_desc: Use image node_id 3 for calling a global function with example usage: make_data_int16(dx, dy, dz) and returns: unknown