title: RecyclerView doesn't recognize the view holder
body: <p>I'm learning Kotlin by building an app and now, I'm trying to create an adapter for my RecyclerView.  However, the name that I chose for my ViewGroup is marked as <code>Unresolved Reference</code>.  I'm fairly new to Kotlin so I knew I was going to make a dumb mistake but in this case, I couldn't figure out what I did wrong.</p>
  
  <pre><code>class RecyclerAdapter: RecyclerView.Adapter&lt;RecyclerAdapter.PosterHolder&gt;(){
  
      override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): {
          TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
      }
  
      override fun getItemCount(): Int {
          TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
      }
  
      override fun onBindViewHolder(holder: RecyclerAdapter.PosterHolder, position: Int) {
          TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
      }
  
  }
  
  class PosterHolder (v: View) : RecyclerView.ViewHolder(v), View.OnClickListener {
      override fun onClick(p0: View?) {
          TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
      }
  }
  </code></pre>