private void initBundle(String baseName, Locale locale) throws IllegalArgumentException{
		ResourceBundle bundle = ResourceBundle.getBundle(baseName, locale);
		lookup = new HashMap<String, String>();
		inverseLookup = new HashMap<String, String>();
		
		Enumeration<String> keys = bundle.getKeys();
		String key;
		String value;
		
		while(keys.hasMoreElements()){
			key = keys.nextElement();
			value = bundle.getString(key);
			
			//since the value now becomes a key, it must be unique.
			if(inverseLookup.containsKey(value)){
				//empty map
				lookup.clear();
				inverseLookup.clear();
				throw new IllegalArgumentException("InMemoryResourceBundle lookup creation failed. Keys AND values must be unique.");
			}
			lookup.put(formatKey(key), value);
			inverseLookup.put(formatKey(value), key);
		}
		//discard resource bundle;
		bundle = null;
	}