def test_extracted_arm_variables_empty(mocker):
    nc_file = request_file(None, None, 'irrad')
    extracted = arm.extract_arm_variables(nc_file, ['no', 'nein', 'ie', 'non'])
    assert extracted.empty
def test_extract_arm_variables_exist(mocker):
    nc_file = request_file(None, None, 'irrad')
    extracted = arm.extract_arm_variables(nc_file,
                                          ['down_short_hemisp', 'nonexistent'])
    assert 'down_short_hemisp' in extracted.columns
    assert 'non-existent' not in extracted.columns