def set_classes(options):
    """
    Auxiliary function to set options['classes'] and delete
    options['class'].
    """
    if 'class' in options:
        assert options not in 'classes'
        options['classes'] = options['class']
        del options['class']
dataset/ETHPy150Open adieu/allbuttonspressed/docutils/parsers/rst/roles.py/set_classes/swapped operands of `not in`