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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 GetPartitionResolver(self, database_link):
 """Gets the partition resolver associated with the database link :param str database_link: Database self link or ID based link. :return: An instance of PartitionResolver. :rtype: object """

        if not database_link:
            raise ValueError("database_link is None or empty.")

        return self.partition_resolvers.get(base.TrimBeginningAndEndingSlashes(database_link))