code: public void renamedEnum(String oldName, Enum<?> currentValue) {
          if (oldName == null) {
              throw new IllegalArgumentException("oldName must not be null");
          }
          if (currentValue == null) {
              throw new IllegalArgumentException("currentValue must not be null");
          }
          checkNotLocked();
          Class<?> enumType = currentValue.getDeclaringClass();
          Map<String, Enum<?>> perClass = enumRenames.get(enumType);
          if (perClass == null) {
              enumRenames.putIfAbsent(enumType, new ConcurrentHashMap<String, Enum<?>>(16, 0.75f, 2));
              perClass = enumRenames.get(enumType);
          }
          perClass.put(oldName, currentValue);
      }
docs: Register the fact that an enum constant was renamed.
  <p>
  This handles the use case where an enum constant is renamed, but the enum class remains the same.
  
  @param oldName  the old name of the enum constant, not null
  @param currentValue  the current enum constant, not null