code: def test_multi_image_result(self):
      source = ogc.WMSRasterSource(self.URI, self.layer)
      crs = ccrs.PlateCarree(central_longitude=180)
      extent = [-15, 25, 45, 85]
      located_images = source.fetch_raster(crs, extent, RESOLUTION)
      assert len(located_images) == 2
  
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 12 for calling the TestWMSRasterSource obj's underlying member method code with example usage: obj.test_multi_image_result() without return types