code: def test_rgb_msk(tiffs):
      with rasterio.open(str(tiffs.join("rgb_msk.tif"))) as src:
          assert np.array_equal(src.dataset_mask(), msk)
          # each band's mask is also equal
          for bmask in src.read_masks():
              assert np.array_equal(bmask, msk)
  
file_path: rasterio/tests/test_dataset_mask.py
imports: from affine import Affine
  import numpy
  import pytest
  from affine import Affine
  import rasterio
  from rasterio.enums import Resampling
  from rasterio.errors import NodataShadowWarning
  from rasterio.crs import CRS
label_desc: Use image node_id 6 for calling a global function with example usage: test_rgb_msk(tiffs) without return types