@classmethod
    def load(cls, filename):
        cls.load_counter_offset = StoreOptions.id_offset()
        val = pickle.load(filename)
        cls.load_counter_offset = None
        return val
Equivalent to pickle.load except that the HoloViews trees is
dataset/ETHPy150Open ioam/holoviews/holoviews/core/options.py/Store.load