@Override
    public String toPattern(boolean escapeUnprintable) {
        if (pat != null && !escapeUnprintable) {
            return pat;
        }
        StringBuilder result = new StringBuilder();
        return _toPattern(result, escapeUnprintable).toString();
    }
@ Override public String toPattern ( boolean escapeUnprintable ) { if ( pat != null && ! escapeUnprintable ) { return pat ; } StringBuilder result = new StringBuilder ( ) ; return _toPattern ( result , escapeUnprintable ) . toString ( ) ; }
Returns a string representation of this set.  If the result of
calling this function is passed to a UnicodeSet constructor, it
will produce another set that is equal to this one.