### Question:
ValueWritableConverter { V fromWritable(Writable writable) { try { @SuppressWarnings("unchecked") V value = (V) fromWritableMethod.invoke(writable); return value; } catch (IllegalAccessException | InvocationTargetException e) { throw new IllegalStateException(e); } } <W extends Writable> ValueWritableConverter(Class<V> valueClass, Class<W> writableClass);   }### Answer:
@Test(expected = NullPointerException.class) public void testFromNull() { new ValueWritableConverter<>(String.class, Text.class).fromWritable(null); }