@Test
  public void testRemoveUnsetConstraint() throws Exception {
    TableDescriptorBuilder builder = TableDescriptorBuilder.newBuilder(name.getTableName());
    Constraints.remove(builder);
    Constraints.remove(builder, AlsoWorks.class);
  }
Test that if a constraint hasn't been set that there are no problems with attempting to remove
it.
hbase-server/src/test/java/org/apache/hadoop/hbase/constraint/TestConstraints.java