code: public static boolean isNumber( Class clazz ) {
        return clazz != null
              && (Byte.TYPE.isAssignableFrom( clazz ) || Short.TYPE.isAssignableFrom( clazz )
                    || Integer.TYPE.isAssignableFrom( clazz ) || Long.TYPE.isAssignableFrom( clazz )
                    || Float.TYPE.isAssignableFrom( clazz ) || Double.TYPE.isAssignableFrom( clazz ) || Number.class.isAssignableFrom( clazz ));
     }
docs: Tests if Class represents a primitive number or wrapper.<br>