docs: public boolean isEmpty() {
          for (int i = 0; i + 1 < array.length; i += 2) {
              int valueNumber = array[i];
              if (valueNumber < 0) {
                  return true;
              }
              int myLockCount = array[i + 1];
              if (myLockCount > 0) {
                  return false;
              }
          }
          return true;
      }