def METHOD_NAME(self, preprocessor):
    """Is a text grade cell not cleared when there is no hidden test region?"""
    cell = create_text_cell()
    cell.source = """assert True"""
    cell.metadata['nbgrader'] = dict()
    resources = dict()
    cell = preprocessor.preprocess_cell(cell, resources, 1)[0]
    assert cell.source == "assert True"
    assert not cell.metadata.nbgrader.get('grade', False)