public int getProviderGrade() {
        return SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT;
    }
Returns the <code>SyncProvider</code> grade of synchronization that
<code>RowSet</code> objects can expect when using this
implementation. As an optimisic synchonization provider, the writer
will only check rows that have been modified in the <code>RowSet</code>
object.
src/main/java/org/replicadb/rowset/sun/rowset/providers/RIOptimisticProvider.java