Will assetbundle automaticly load instead of download if its already present on the device

so i want to be able to download entire scenes into my app (i will call it dlc for now), assetbundles seemed to be the way to go but i am not sure how unity handles assetbundles right now i’m considering the following approach.

public void loadLevel ()
    {
    	//checking if the scene is already loaded
    	if (sceneName.isloaded){
    		//feedbackloop
    	}
    	else{
    		//checking if the assetbundle is downloaded on the device
    		if ( "no clue to what i should put in here"){
    			//load scene
    		}
                else{
                       //download assetbundle
                       //load scene
                {
    	}
}

WWW.LoadFromCacheOrDownload might be helpful.