docs: public boolean contains(final Object value)
      {
          final Object[] values = this.values;
          final int mask = values.length - 1;
          int index = value.hashCode() & mask;
  
          while (values[index] != MISSING_VALUE)
          {
              if (values[index].equals(value))
              {
                  return true;
              }
  
              index = next(index, mask);
          }
  
          return false;
      }