AssetBundle Load

 var asset : AssetBundle;    
 ...    
 asset.Load("assetName");
 asset.Load("assetName");

Does this code create two instances of the "assetName" or the 2nd call just returns the result of the first call?

I need to load some texture from my AssetBundle, but I don't know should I check that I loaded this texture before or I can just call Load() and I can be sure it will not cause memory leaks?