private static TableDescriptorBuilder addConstraint(TableDescriptorBuilder builder,
    Class<? extends Constraint> clazz, Configuration conf, long priority) throws IOException {
    return writeConstraint(builder, serializeConstraintClass(clazz),
      configure(conf, true, priority));
  }
Write the raw constraint and configuration to the descriptor.
<p/>
This method takes care of creating a new configuration based on the passed in configuration and
then updating that with enabled and priority of the constraint.
<p/>
When a constraint is added, it is automatically enabled.
hbase-server/src/main/java/org/apache/hadoop/hbase/constraint/Constraints.java