public static void assertHasSinglePrivateConstructor(Class<?> cls) throws Exception {
    Constructor<?>[] constructors = cls.getDeclaredConstructors();
    assertEquals("expected number of constructors to be == 1", 1, constructors.length);

    Constructor<?> constructor = constructors[0];
    assertFalse("expected constructor to be inaccessible", constructor.isAccessible());

    constructor.setAccessible(true);
    constructor.newInstance();
  }
Provides common utilities helpful for testing.
jobdispatcher/src/testLib/com/firebase/jobdispatcher/TestUtil.java