case 1:
          return 1;
        case -1:
          return ((k & 1) == 0) ? 1 : -1;
        case 2:
          checkNoOverflow(k < Long.SIZE - 1, "checkedPow", b, k);
          return 1L << k;
        case -2:
          checkNoOverflow(k < Long.SIZE, "checkedPow", b, k);
          return ((k & 1) == 0) ? (1L << k) : (-1L << k);
        default:
          throw new AssertionError();
      }