code: def test_read_boundless_masks_zero_stop(rgb_byte_tif_reader):
      with rgb_byte_tif_reader as src:
          data = src.read_masks(
              window=((-200, 0), (-200, 0)), boundless=True
          )
          assert data.shape == (3, 200, 200)
          assert data.min() == data.max() == src.nodata
  
imports: import numpy
  import pytest
  import rasterio
  from rasterio.enums import Resampling
  from rasterio.windows import Window
label_desc: Use image node_id 13 for calling a global function with example usage: test_read_boundless_masks_zero_stop(rgb_byte_tif_reader) without return types