return AnyMatcher.getInstance();
return NoMatcher.getInstance();
    public Matcher getChangingMatcher() {        if (_changingPattern == null) {            return AnyMatcher.getInstance();        }        PatternMatcher matcher = _ivy.getMatcher(_changingMatcherName);        if (matcher == null) {            throw new IllegalStateException("unknown matcher '"+_changingMatcherName+"'. It is set as changing matcher in "+this);        }        return matcher.getMatcher(_changingPattern);    }