rem: status_t WriteBack(Transaction *transaction) { if (transaction == NULL || fBlock == NULL) RETURN_ERROR(B_BAD_VALUE);
add: CachedBlock::WriteBack(Transaction *transaction) { if (transaction == NULL || fBlock == NULL) RETURN_ERROR(B_BAD_VALUE);
context: 		status_t WriteBack(Transaction *transaction)		{			if (transaction == NULL || fBlock == NULL)				RETURN_ERROR(B_BAD_VALUE);			return transaction->WriteBlocks(fBlockNumber, fBlock);		}