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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 chain(self, operation=ChainOperator.AND):
 """ Start a chain operation :param ChainOperator, str operation: how to combine with a new one :rtype: Query """

        if isinstance(operation, str):
            operation = ChainOperator(operation)
        self._chain = operation
        return self