presto-main/src/main/java/io/prestosql/metadata/InternalBlockEncodingSerde.java/InternalBlockEncodingSerde/writeLengthPrefixedString
class InternalBlockEncodingSerde:    private static void writeLengthPrefixedString(SliceOutput output, String value)
    {
        byte[] bytes = value.getBytes(UTF_8);
        output.writeInt(bytes.length);
        output.writeBytes(bytes);
    }