code: def id(x, y, z):
      return x, y, z
  
imports: import copy
  import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_equal
  from ...transforms.affine_transform import AffineTransform
  from ...transforms.affine_utils import from_matrix_vector
  from ...transforms.transform import Transform
  from ..volume_img import CompositionError, VolumeImg
label_desc: Use image node_id 2 for calling a global function with example usage: id(x, y, z) and returns: x,  y,  z