def __getitem__(self, key):
        if self.validProperties not in key:
            raise ValueError("Invalid %s property: %s" %
                             (self.__class__.__name__, repr(key)))
        return self.properties.get(key)
dataset/ETHPy150Open brendonh/pyth/pyth/document.py/_PythBase.__getitem__/swapped operands of `not in`