code: def mock_cmgdem(tmpdir, url):
      """Create fake file representing CMGDEM.hdf."""
      yield from _mock_and_create_dem_file(
          tmpdir, url, "averaged elevation", fill_value=-9999
      )
  
imports: from contextlib import contextmanager
  from datetime import datetime
  from unittest import mock
  import numpy
  import pytest
  import xarray
  from dask import array
  from pyresample.geometry import AreaDefinition
  from satpy.tests.utils import assert_maximum_dask_computes
label_desc: Use image node_id 1 for calling a global function with example usage: mock_cmgdem(tmpdir, url) without return types