class_docstr: Test the Scene object's `.load` method for composites.
class_docstr_tok: ["Test","the","Scene","object","'s","`",".load","`","method","for","composites","."]
docstr: Test loading a composite whose prerequisites can't be loaded.
  
  Note that the prereq exists in the reader, but fails in loading.
code: def test_load_comp15(self):
      """Test loading a composite whose prerequisites can't be loaded.
  
      Note that the prereq exists in the reader, but fails in loading.
  
      """
      # it is fine that an optional prereq doesn't exist
      scene = Scene(filenames=["fake1_1.txt"], reader="fake1")
      scene.load(["comp15"])
      loaded_ids = list(scene._datasets.keys())
      assert not loaded_ids
  
imports: from unittest import mock
  import pytest
  import xarray
  from dask import array
  from satpy import Scene
  from satpy.tests.utils import make_cid, make_dataid, make_dsq, spy_decorator
label_desc: Use image node_id 5 for calling the TestLoadingComposites obj's underlying member method code with example usage: obj.test_load_comp15() without return types