code: def test_types():
      lx = 70
      ly = 100
      data, labels = make_2d_syntheticdata(lx, ly)
      data = 255 * (data - data.min()) // (data.max() - data.min())
      data = data.astype(np.uint8)
      with expected_warnings(
          [f"{PYAMG_MISSING_WARNING}|scipy.sparse.linalg.cg"]
      ):
          labels_cg_mg = random_walker(
              data, labels, beta=90, mode="cg_mg"
          )
      assert (labels_cg_mg[25:45, 40:60] == 2).all()
      assert data.shape == labels.shape
  
imports: import numpy
  from skimage._shared import testing
  from skimage._shared._warnings import expected_warnings
  from skimage._shared.testing import xfail, arch32
  from skimage.segmentation import random_walker
  from skimage.transform import resize
label_desc: Use image node_id 7 for calling a global function with example usage: test_types() without return types