title: Check for null before select on linq
body: <p>I have just installed ReSharper, and it has altered</p>
  
  <pre><code>if(dto != null)
  {
      return new test{
       obj1 = "",
       obj2 = "",
   }
  }
  </code></pre>
  
  <p>into</p>
  
  <pre><code> return dto?.Select(item =&gt; new test
        {
      return new test{
       obj1 = "",
       obj2 = "",
   }
  </code></pre>
  
  <p>I have not seen before</p>
  
  <pre><code>dto?.Select
  </code></pre>
  
  <p>tried to google the meaning with no luck.. could someone please explain , or point me in the right direction to the deffination</p>
  
  <p>I gather its simply checking for null?</p>