code: def test_boundless_fill_value_overview_masks():
      """Confirm a more general resolution to issue #1471"""
      with rasterio.open("tests/data/cogeo.tif") as src:
          data = src.read(
              1,
              boundless=True,
              window=Window(-300, -335, 1000, 1000),
              fill_value=5,
              out_shape=(512, 512),
          )
      assert (data[:, 0] == 5).all()
  
imports: from affine import Affine
  import shutil
  from hypothesis import example, given
  import hypothesis.strategies
  import numpy
  from numpy.testing import assert_almost_equal
  import pytest
  import rasterio
  from rasterio.io import MemoryFile
  from rasterio.windows import Window
label_desc: Use image node_id 10 for calling a global function with example usage: test_boundless_fill_value_overview_masks() without return types