@Override
  public Optional<RegionObserver> getRegionObserver() {
    return Optional.of(this);
  }
Processes multiple {@link Constraint Constraints} on a given table.
<p>
This is an ease of use mechanism - all the functionality here could be implemented on any given
system by a coprocessor.
hbase-server/src/main/java/org/apache/hadoop/hbase/constraint/ConstraintProcessor.java