code: public boolean containsKey(Object key) {
  		CacheLine line = (CacheLine) cacheLineTable.get(key);
  
  		if (hasExpired(line)) {
  			removeObject(key);
  			line = null;
  		}
  		if (line != null) {
  			return true;
  		} else {
  			return false;
  		}
  	}
docs: Returns a boolean specifying whether or not an element with the specified
  key is in the cache. If the requested element hasExpired, it is removed
  before it is looked up which causes the function to return false.
  
  @param key
  The key for the element, used to reference it in the hastables
  and LRU linked list
  @return True is the cache contains an element corresponding to the
  specified key, otherwise false