code: public static Class<?>[] primitivesToWrappers(final Class<?>... classes) {
          if (classes == null) {
              return null;
          }
  
          if (classes.length == 0) {
              return classes;
          }
  
          final Class<?>[] convertedClasses = new Class[classes.length];
          for (int i = 0; i < classes.length; i++) {
              convertedClasses[i] = primitiveToWrapper(classes[i]);
          }
          return convertedClasses;
      }
docs: <p>Converts the specified array of primitive Class objects to an array of
  its corresponding wrapper Class objects.</p>
  
  @param classes  the class array to convert, may be null or empty
  @return an array which contains for each given class, the wrapper class or
  the original class if class is not a primitive. {@code null} if null input.
  Empty array if an empty array passed in.
  @since 2.1