void flushRange() {
            if (fromC > prevC) {
                return; // handle initial condition
            }
            append(fromC);
            if (fromC < prevC) {
                token.append('-');
                append(prevC);
                ++charCnt;
            }
            token.append(',');
            if (++charCnt > 16) {
                token.append('\n');
                charCnt = 0;
            }
        }
Removes leading and trailing quotation mark from the given string. This method will properly unescape whatever
content is withing the string literal as well.

@param str The string to unquote.
@return The unquoted string.
vespajlib/src/main/java/com/yahoo/javacc/UnicodeUtilities.java