public Integer evaluate(final Integer value) {
      try {
        Thread.sleep(100);
      } catch (InterruptedException e) {
        // No-op
      }
      return value;
    }
Test the cancellation of a query that is running.
We spawn 2 threads - one running the query and
the other attempting to cancel.
We're using a dummy udf to simulate a query,
that runs for a sufficiently long time.
@throws Exception
itests/hive-unit/src/test/java/org/apache/hive/jdbc/cbo_rp_TestJdbcDriver2.java