docs: private void setMetaClass(Class theClass, MetaClass oldMc, MetaClass newMc) {
          final ClassInfo info = ClassInfo.getClassInfo(theClass);
          
          MetaClass mc = null;
          info.lock();
          try {
              mc = info.getStrongMetaClass();
              info.setStrongMetaClass(newMc);
          } finally {
              info.unlock();
          }
          if ((oldMc == null && mc != newMc) || (oldMc != null && mc != newMc && mc != oldMc)) {
              fireConstantMetaClassUpdate(null, theClass, mc, newMc);
          }
      }