presto-spi/src/main/java/io/prestosql/spi/type/Chars.java/Chars/compareChars
class Chars:    public static int compareChars(Slice left, Slice right)
    {
        if (left.length() < right.length()) {
            return compareCharsShorterToLonger(left, right);
        }
        else {
            return -compareCharsShorterToLonger(right, left);
        }
    }