code: @Override
  	public final Bitmap get(String key) {
  		if (key == null) {
  			throw new NullPointerException("key == null");
  		}
  
  		synchronized (this) {
  			return map.get(key);
  		}
  	}
docs: Returns the Bitmap for {@code key} if it exists in the cache. If a Bitmap was returned, it is moved to the head
  of the queue. This returns null if a Bitmap is not cached.