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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def queryFilter(self, function=None):
 """ Defines a decorator that can be used to filter queries. It will assume the function being associated with the decorator will take a query as an input and return a modified query to use. :usage class MyModel(orb.Model):
 objects = orb.ReverseLookup('Object') @classmethod @objects.queryFilter() def objectsFilter(cls, query, **context):
 return orb.Query() :param function: <callable> :return: <wrapper> """

        if function is not None:
            self.__query_filter = function
            return function

        def wrapper(func):
            self.__query_filter = func
            return func
        return wrapper