code: private LazyFileBasedLongCollection getCollectionForKey(final K key) {
  
  		LazyFileBasedLongCollection collection = hashFiles.get(key);
  		if (collection == null) {
  
  			collection = new LazyFileBasedLongCollection(basePath + File.separator + key.hashCode() + ".lfc", clearOnOpen);
  			hashFiles.put(key, collection);
  		}
  
  		return collection;
  	}
docs: ----- private methods -----