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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 find_one(cls, *args, **kwargs):
 """Run a find_one on this model's collection. The arguments to ``Model.find_one`` are the same as to ``pymongo.Collection.find_one``."""

        database, collection = cls._collection_key.split('.')
        return current()[database][collection].find_one(*args, **kwargs)