code: def test_array_protocol():
      mat = np.eye(4)
      tf = ProjectiveTransform(mat)
      assert_equal(np.array(tf), mat)
      assert_equal(np.array(tf, dtype=int), mat.astype(int))
  
imports: import re
  import textwrap
  import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_almost_equal, assert_equal
  from skimage.transform import AffineTransform, EssentialMatrixTransform, EuclideanTransform, FundamentalMatrixTransform, PiecewiseAffineTransform, PolynomialTransform, ProjectiveTransform, SimilarityTransform, estimate_transform, matrix_transform
  from skimage.transform._geometric import _GeometricTransform, _affine_matrix_from_vector, _center_and_normalize_points, _euler_rotation_matrix
label_desc: Use image node_id 44 for calling a global function with example usage: test_array_protocol() without return types