title: Unable to write an Include query with FirstOrDefault() and condition
body: <p>I'm writing an entity framework query which needs Eager loading multiple levels based on condition.</p>
  
  <pre><code>var blogs1 = context.Blogs
      .Include(x =&gt; x.Posts.FirstOrDefault(h =&gt; h.Author == "Me"))
      .Include(x =&gt; x.Comment)
      .FirstOrDefault();
  
  public class Blog
  {
      public int BlogId { get; set; }
      public virtual ICollection&lt;Post&gt; Posts { get; set; }
  }
  
  
  public class Post
  {
      public int PostId { get; set; }
      public string Author { get; set; }  
      public int BlogId { get; set; }
      public virtual ICollection&lt;Comment&gt; Comments { get; set; }
  }
  
  public class Comment
  {
      public int PostId
      public int CommentId { get; set; }
      public string CommentValue { get; set;}
  }
  var blogs2 = context.Blogs
                          .Include("Posts.Comments")
                          .ToList(); 
  </code></pre>
  
  <p>I expect result to have first or default Blog and first  or default Post for that blog by author "Me" and a list of all comments.</p>
  
  <p>When query for <code>blogs1</code>is executed I see following exception
  <code>blogs2</code> query works as expected</p>
  
  <p><code>The Include path expression must refer to a navigation property defined on the type. Use dotted paths for reference navigation properties and the Select operator for collection navigation properties.
  Parameter name: path</code></p>