title: SQLKata return complex object with Include/IncludeMany
body: <p>I need to return from a query a list of students where each students has assignments.</p>
  <pre><code>class Student {
    public string Name{ get; set; }
    public IEnumerable&lt;Assignment&gt; Assignments{ get; set; }
  }
  
  class Assignment { 
    public string Title { get; set; } 
  }
  </code></pre>
  <p>so tried to create two queries and then use include/includemany but i get other errors (The given key 'Id' was not present in the dictionary)</p>
  <pre><code>var students = db.Query('Student')
      .Select(...)
      .Where()
  
  var assignments= db.Query('Assignment')
      .Select(...)
      .Where()
  
  var result = students.IncludeMany('Assignments', assignments).Get()
  </code></pre>
  <p>but this does not work. How can you properly create complex/nested objects with SQLKata?</p>