static Set<String> findAllArgs(String imageTagString) {
        Matcher m = Pattern.compile(ARG_PATTERN_REGEX).matcher(imageTagString);
        Set<String> args = new HashSet<>();
        while(m.find()){
            if(m.group(1)!=null){
                args.add(m.group(1));
            }else if(m.group(2)!=null){
                args.add(m.group(2));
            }
        }
        return args;
    }
Helper method for extractArgs(exposed for test)

@param argLines list of string arrays containing lines with words
@return map of parsed arguments
src/main/java/io/fabric8/maven/docker/util/DockerFileUtil.java