public int getDataSourceLock() throws SyncProviderException {
        return SyncProvider.DATASOURCE_NO_LOCK;
    }
Returns the active data source lock severity in this
reference implementation of the <code>SyncProvider</code>
abstract class.

@return <code>SyncProvider.DATASOURCE_NO_LOCK</code>.
    The reference implementation does not support data source locks.
src/main/java/org/replicadb/rowset/sun/rowset/providers/RIOptimisticProvider.java