title: LiveData is passing null to observer
body: <p>I have the following code</p>
  
  <pre><code>myViewModel.catLiveData.observe(this,Observer{
    if(it==null){
        Log.d(TAG,"the object returned is null! How is that possible?")
    }else{ doWork(it) }
  })
  </code></pre>
  
  <p>How is it possible that I am getting null? I thought LiveData is not supposed to pass null to the observer? This LiveData is listening to Room Entity, by the way.</p>