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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 get_instance(cls, dependencies=None):
 """ Return an instance for a contract name. :param dependencies: :return: Contract base instance """

        assert cls is not ContractBase, 'ContractBase is not meant to be used directly.'
        assert cls.CONTRACT_NAME, 'CONTRACT_NAME must be set to a valid keeper contract name.'
        return cls(cls.CONTRACT_NAME, dependencies)