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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 query(self, *args, **kwargs):
 """ Generic query method. In reality, your storage class would have its own query methods, Performs a Mongo find on the Marketdata index metadata collection. See: http://api.mongodb.org/python/current/api/pymongo/collection.html """

        for x in self._collection.find(*args, **kwargs):
            x['stuff'] = cPickle.loads(x['stuff'])
            del x['_id'] # Remove default unique '_id' field from doc 
            yield Stuff(**x)