private Throwable getConstraintException(Throwable t) {
    while (t != null) {
      if (t instanceof SQLIntegrityConstraintViolationException) {
        return t;
      }
      t = t.getCause();
    }
    return null;
  }
This is a cleanup method which is used to rollback a active transaction
if the success flag is false and close the associated Query object. This method is used
internally and visible for testing purposes only
@param success Rollback the current active transaction if false
@param query Query object which needs to be closed
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java