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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(self, filter=None):
 """ Finds one matching query element :param query: dictionary representing the mongo query :return: the resulting document (if found) """


        if self.table is None:
            self.build_table()

        allcond = self.parse_query(filter)

        return self.table.get(allcond)