code: @SuppressWarnings("unchecked")
          public static <T> ClassSup<T> cls(String clsName) {
                  try {
                          return mapper.get(clsName, () -> (ClassSup<T>) cls(Class.forName(clsName)));
                  } catch (Exception e) {
                          throw $(e);
                  }
          }
docs: create a class supporter with given class name
  
  @param clsName full name of the class to be supported
  @return Class supporter
  @see ClassSup