presto-orc/src/main/java/io/prestosql/orc/reader/SliceColumnReader.java/SliceColumnReader/getMaxCodePointCount
class SliceColumnReader:    private static int getMaxCodePointCount(Type type)
    {
        if (isVarcharType(type)) {
            VarcharType varcharType = (VarcharType) type;
            return varcharType.isUnbounded() ? -1 : varcharType.getBoundedLength();
        }
        if (isCharType(type)) {
            return ((CharType) type).getLength();
        }
        if (isVarbinaryType(type)) {
            return -1;
        }
        throw new IllegalArgumentException("Unsupported encoding " + type.getDisplayName());
    }