title: Scala warning match may not be exhaustive
body: <p>I am somewhat new to Scala. Following is my code.</p>
  
  <pre><code>Option(Session.get().getAttribute("player")) match {
    case None =&gt; {
      val player = new Player(user.getEmail, user.getNickname).createOrGet
      Session.get().setAttribute("player", player)
    }
  }
  </code></pre>
  
  <p>I get the following warning when compiling</p>
  
  <pre><code>Warning:(35, 11) match may not be exhaustive.
  It would fail on the following input: Some(_)
      Option(Session.get().getAttribute("player")) match {
            ^
  </code></pre>
  
  <p>How do I fix this? Is there a way to rewrite the code to avoid the warning?(I am using Scala version 2.10.2)</p>