### Question:
DescriptorServiceImpl extends ServiceSupport implements DescriptorService { public Descriptor getDescriptor(final String className) { checkNotNull(className, "class name"); return getHudson().getDescriptor(className); } @Inject  DescriptorServiceImpl(); Descriptor getDescriptor(final String className); Descriptor getDescriptor(Class<? extends Describable> type); Descriptor getDescriptorOrDie(Class<? extends Describable> type); T getDescriptorByType(Class<T> type); DescriptorExtensionList<T, D> getDescriptorList(
            Class<T> type);  }### Answer:
@Test(expected = NullPointerException.class) public void getDescriptorNullArg() { getInst().getDescriptor((String) null); }
@SuppressWarnings({ "rawtypes", "unchecked" }) @Test(expected = NullPointerException.class) public void getDescriptorByTypeNullArg() { getInst().getDescriptor((Class) null); }