### Question:
ClassNameUtils { public static @Nullable String getWrapper(String className) { String internalName = toFormat(className, TypeFormat.INTERNAL); String wrapperName = internalPrimitiveToWrapper.get(getComponentBase(internalName)); if (null == wrapperName) { return null; } StringBuilder sb = new StringBuilder(); int dimensionCount = getDimensionCount(internalName); if (dimensionCount > 0) { for (int i = 0; i < dimensionCount; i++) { sb.append('['); } sb.append('L').append(wrapperName).append(';'); return sb.toString(); } return wrapperName; }  static String binaryToInternal(String binaryName); static String getComponentBase(String className); static String getComponentType(String className); static int getDimensionCount(String className); static String getPackageName(String className); static @Nullable String getPrimitive(String className); static Class<?> getPrimitiveClass(String className); static @Nullable String getWrapper(String className); static String internalToBinary(String internalName); static String internalToSource(String internalName); static boolean isObject(String type); static boolean isPrimitive(String className); static boolean isPrimitiveOrWrapper(String className); static boolean isWrapper(String className); static String sourceToBinary(String sourceName); static String sourceToInternal(String sourceName); static String toFormat(String className, TypeFormat format); static String toInternal(Class<?> klazz); static List<String> toInternal(Class<?>... classes); static ReferenceType guessReferenceType(@Nonnull String s);  }### Answer:
@Test public void canGetPrimitiveWrapper() { for (Entry<String, Class<?>> entry : internalPrimitiveToWrapperClass.entrySet()) { String className = entry.getKey(); String expected = entry.getValue().getName(); String actual = ClassNameUtils.getWrapper(className); assertEquals(expected, actual); } }