@Test
  public void testNullClassLoader() {
    try {
      new AddToClassPathAction(null, Collections.emptyList());
      fail("When pafrent class loader is null, IllegalArgumentException is expected!");
    } catch (IllegalArgumentException e) {
      // pass
    }
  }
Minimal tests for AddToClassPathAction class. Most of the tests don't use
{@link java.security.AccessController#doPrivileged(java.security.PrivilegedAction)},
presumably the tests will not be executed under security manager.
ql/src/test/org/apache/hadoop/hive/ql/exec/TestAddToClassPathAction.java