Merge two Hashtable<String, Integer>

    private static Hashtable<String, Integer> getEventCountMap(Hashtable<String, Integer> eventCountMap,
			Hashtable<String, Integer> otherEventCountMap)
	{
		Hashtable<String, Integer> mergeEventCountMap = new Hashtable<String, Integer>();
		mergeEventCountMap.putAll(eventCountMap);
		Set<Entry<String, Integer>> entries = otherEventCountMap.entrySet();
		for (Entry<String, Integer> entry : entries)
		{
			String key = entry.getKey();
			Integer value = entry.getValue();
			Integer oldValue = mergeEventCountMap.get(key);
			if (oldValue != null)
			{
				value += oldValue;
			}
			mergeEventCountMap.put(key, value);
		}
		return mergeEventCountMap;
	}