@Test public void rejectionOfNullMethods() {
    try {
      new EventHandler(this, null);
      fail("EventHandler must immediately reject null methods.");
    } catch (NullPointerException expected) {
      // Hooray!
    }
  }
Checks that EventHandler's constructor disallows null methods.
otto/src/test/java/com/squareup/otto/EventHandlerTest.java