@grammar((list, KeyedList))
    def marks(value):
        for i, entry in enumerate(value):
            _assert_is_type('marks[{0}]'.format(i), entry, Mark)
Return internal state; can be passed to setstate() later.
dataset/ETHPy150Open wrobstory/vincent/vincent/visualization.py/Visualization.marks--crossover with--dataset/ETHPy150Open babble/babble/include/jython/Lib/random.py/WichmannHill.getstate