code: private static boolean match(char c, long lowMask, long highMask) {
          if (c < 64)
              return ((1L << c) & lowMask) != 0;
          if (c < 128)
              return ((1L << (c - 64)) & highMask) != 0;
          return false;
      }
docs: Tell whether the given character is permitted by the given mask pair