title: EF Core 1.0 - Include() generates more than one queries
body: <p>I am using EF 7.0.0-rc1-final.</p>
  
  <p>The following statement generates multiple queries on the server.
  Is this normal or I am missing something ?</p>
  
  <pre><code>Group myGroup = dbContext_
              .Set&lt;Group&gt;()
              .Include(x =&gt; x.GroupRoles)
              .ThenInclude(x =&gt; x.Role)
              .FirstOrDefault(x =&gt; x.Name == "Approver");
  </code></pre>
  
  <p>I see two separate queries executed on the server:</p>
  
  <p><a href="https://i.stack.imgur.com/VD77x.png" rel="noreferrer"><img src="https://i.stack.imgur.com/VD77x.png" alt="Query 1"></a></p>
  
  <p>And</p>
  
  <p><a href="https://i.stack.imgur.com/RY8de.png" rel="noreferrer"><img src="https://i.stack.imgur.com/RY8de.png" alt="Query 2"></a></p>
  
  <p>It's a standard many-to-many scenario. Why is the first query ?</p>
  
  <p>Thanks</p>