@Test public void rejectionOfNullTargets() throws NoSuchMethodException {
    Method method = getRecordingMethod();
    try {
      new EventProducer(null, method);
      fail("EventProducer must immediately reject null targets.");
    } catch (NullPointerException expected) {
      // Huzzah!
    }
  }
Checks that EventProducer's constructor disallows null targets.
otto/src/test/java/com/squareup/otto/EventProducerTest.java