Utility { public static Long timeStampInNanos(Timestamp timestamp) { try { if (timestamp == null) { return null; } return Math.addExact(Math.multiplyExact(timestamp.getSeconds(), SCALAR), timestamp.getNanos()); } catch (ArithmeticException e) { throw new ArithmeticException("Long overflow when converting Timestamp to nanos timestamp: " + timestamp); } }  static Pair<byte[], byte[]> extractHashAndSigFromFile(File file); static String getBalanceFileHash(String fileName); static RecordFile parseRecordFile(String filePath, Consumer<RecordItem> recordItemConsumer); static int readInt(DataInputStream dis, MessageDigest md); static byte[] readBytes(DataInputStream dis, int len, MessageDigest md); static Timestamp instantToTimestamp(Instant instant); static String accountIDToString(AccountID accountID); static Instant convertToInstant(Timestamp timestamp); static String printProtoMessage(GeneratedMessageV3 message); static String bytesToHex(byte[] bytes); static Long convertToNanos(long second, long nanos); static Long convertToNanosMax(long second, long nanos); static Long timeStampInNanos(Timestamp timestamp); static Long timestampInNanosMax(Timestamp timestamp); static boolean hashIsEmpty(String hash); static void archiveFile(File source, Path destinationRoot); static void purgeDirectory(Path path); static void ensureDirectory(Path path); static File getResource(String path); static final Instant getInstantFromFilename(String filename); static final long getTimestampFromFilename(String filename); static final String getStreamFilenameFromInstant(StreamType streamType, Instant instant); static final boolean isStreamFileAfterInstant(String filename, Instant instant); static @Nullable String protobufKeyToHexIfEd25519OrNull(@Nullable byte[] protobufKey); static TransactionID getTransactionId(AccountID payerAccountId); static boolean verifyHashChain(
            String actualPrevFileHash, String expectedPrevFileHash, Instant verifyHashAfter, String fileName); static final Instant MAX_INSTANT_LONG; }
@Test @DisplayName("converting illegal timestamp to nanos") void convertTimestampToNanosIllegalInput() { Timestamp timestamp = Timestamp.newBuilder().setSeconds(1568376750538L).setNanos(0).build(); assertThrows(ArithmeticException.class, () -> { Utility.timeStampInNanos(timestamp); }); }