code: @Override
      public boolean isEligibleFor(Object criterion) {
          return Class.class.isInstance(criterion)
              && ((Class<?>) criterion).isAssignableFrom(getClass());
      }
docs: Returns <code>true</code> if the `criterion`
  is of the same class or a base class of this event's class.
  
  @see org.jgrapes.core.Eligible#isEligibleFor(java.lang.Object)