docs: static boolean isValid(int type) {
          // make sure this is always synchronized with Zoodefs!!
          switch (type) {
          case OpCode.notification:
              return false;
          case OpCode.create:
          case OpCode.delete:
          case OpCode.createSession:
          case OpCode.exists:
          case OpCode.getData:
          case OpCode.setData:
          case OpCode.sync:
          case OpCode.getACL:
          case OpCode.setACL:
          case OpCode.getChildren:
          case OpCode.getChildren2:
          case OpCode.ping:
          case OpCode.closeSession:
          case OpCode.setWatches:
              return true;
          default:
              return false;
          }
      }