### Question:
PrimitiveUtils { public static String getPrimitiveTypeNameFromWrapper(Class<?> type) { return wrapperTypes.get(type); } private  PrimitiveUtils(); static Object getEmptyValue(Class<?> type); static Class<?> getWrapperType(Class<?> type); static boolean isPrimitiveWrapper(Class<?> type); static String getPrimitiveTypeNameFromWrapper(Class<?> type);  }### Answer:
@Test public void getPrimitiveTypeNameFromWrapper() { assertPrimitiveName(Byte.TYPE, Byte.class); assertPrimitiveName(Short.TYPE, Short.class); assertPrimitiveName(Integer.TYPE, Integer.class); assertPrimitiveName(Long.TYPE, Long.class); assertPrimitiveName(Float.TYPE, Float.class); assertPrimitiveName(Double.TYPE, Double.class); assertNull(PrimitiveUtils.getPrimitiveTypeNameFromWrapper(getClass())); assertNull(PrimitiveUtils.getPrimitiveTypeNameFromWrapper(Long.TYPE)); }