code: def test_fetch_img(self):
      source = ogc.WMSRasterSource(self.URI, self.layer)
      extent = [-10, 10, 40, 60]
      (located_image,) = source.fetch_raster(
          self.projection, extent, RESOLUTION
      )
      img = np.array(located_image.image)
      assert img.shape == RESOLUTION + (4,)
      # No transparency in this image.
      assert img[:, :, 3].min() == 255
      assert extent == located_image.extent
  
imports: from unittest import mock
  from xml.etree.ElementTree import ParseError
  import numpy
  import pytest
  import cartopy.crs
  from cartopy.tests.conftest import _HAS_PYKDTREE_OR_SCIPY
  import cartopy.io.ogc_clients
  from cartopy.io.ogc_clients import _OWSLIB_AVAILABLE
label_desc: Use image node_id 10 for calling the TestWMSRasterSource obj's underlying member method code with example usage: obj.test_fetch_img() without return types