presto-rcfile/src/main/java/io/prestosql/rcfile/text/StringEncoding.java/StringEncoding/encodeValueInto
class StringEncoding:    @Override
    public void encodeValueInto(int depth, Block block, int position, SliceOutput output)
    {
        Slice slice = type.getSlice(block, position);
        if (escapeByte != null && slice.indexOfByte(escapeByte) < 0) {
            throw new IllegalArgumentException("escape not implemented");
        }
        output.writeBytes(slice);
    }