How to store long number as 64 bit encoded value in Bigtable?

When using readModifyWrite method to increment a number it throws exception the value must be stored as 64 bit encoded signed integer in Java. How to store it as 64 bit big endian? I tried reversebytes method and Base64 encoding but didn't help.

Found thru' Google support :

long number = 456712L; 
    ByteString encodedLong = ByteString.copyFrom(
        ByteBuffer.allocate(Long.BYTES).putLong(number).array()
    );
    
    Mutation mutation = Mutation.create(tableId, rowKey)
        .setCell(columnFamily, columnQualifier, encodedLong);
    dataClient.mutateRow(mutation);

    Row row = dataClient.readRow(tableId, rowKey);
    if (row != null && row.getCells(columnFamily, columnQualifier).size() > 0) {
        ByteString longBytes = row.getCells(columnFamily, columnQualifier).get(0).getValue();
        long longValue = ByteBuffer.wrap(longBytes.toByteArray()).getLong();

        System.out.println("Retrieved long value: " + longValue); 
    } else {
        System.out.println("Long value not found for row key: " + rowKey);
    }