code: void eitherZeroOrOneOrAddress(String command) {
      if (!isAddressCommand && !(isZeroCommand ^ isOneCommand)) {
        throwException(CMD + command + ": (zero|one) specified incorrectly");
      }
      if (isAddressCommand && (isZeroCommand || isOneCommand)) {
        throwException(CMD + command + ": cannot specify address with (zero|one)");
      }
    }
docs: Check if either -zero -one or -address are specified.