docs: public static <E extends Enum<E>> long getLongFlag(EnumSet<E> eSet)
      {
          long flag = 0;
          for (Enum<E> en : eSet)
          {
              long ordinal = en.ordinal();
              if (ordinal >= Long.SIZE)
              {
                  throw new IllegalArgumentException(eSet+" contains too many enums for long");
              }
              flag |= 1 << ordinal;
          }
          return flag;
      }