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