@Override
public LocalThreePhaseCommitCohort onTransactionReady(@Nonnull DOMStoreWriteTransaction tx,
@Nullable Exception operationError) {
+ Preconditions.checkArgument(tx instanceof SnapshotBackedWriteTransaction);
if (operationError != null) {
return new LocalChainThreePhaseCommitCohort((SnapshotBackedWriteTransaction<TransactionIdentifier>)tx,
operationError);