keyIt fixed

    public String generateResponse(HashSet<String> words)
    {
        Iterator<String> it = words.iterator();
        while(it.hasNext())
        {
            String word = it.next();
            ArrayList<String> keys = new ArrayList<String>();
            keys.addAll(responseMap.keySet());
            while(keys.hasNext())
            {
                 String key = keys.next();
                 if (word.contains(key))
                 {
                     String response = responseMap.get(word);
                 }
            }
            if(response != null)
            {
                 return response;
            }

        }
        // If we get here, none of the words from the input line was recognized.
        // In this case we pick one of our default responses (what we say when
        // we cannot think of anything else to say...)
        return pickDefaultResponse();
    }