def __setitem__(self, key, value):
        if key in self:
            l = super().__getitem__(key)
            # if value already there don't add it.
            # I'm not sure this is the correct way of doing thing but
            # it makes sense not to have repeating items
            if l not in value:
                l.append(value)
        else:
            super().__setitem__(key, [value])
dataset/ETHPy150Open quantmind/pulsar/pulsar/utils/structures/misc.py/MultiValueDict.__setitem__/swapped operands of `not in`