docs: public boolean containsKey(final int key)
      {
          @DoNotSub final int mask = values.length - 1;
          @DoNotSub int index = Hashing.hash(key, mask);
  
          boolean found = false;
          while (null != values[index])
          {
              if (key == keys[index])
              {
                  found = true;
                  break;
              }
  
              index = ++index & mask;
          }
  
          return found;
      }