title: Convert ToList() to a list of MyObject
body: <p>I'm trying to convert a <code>List</code> of <code>MyObject</code> that I'm doing operation on by using LINQ and turning back to a list of <code>MyObject</code>.</p>
  
  <pre><code>public class Part
  {
      public string ID { get; set; }
      public string DescFr { get; set; }
      public string DescEng { get; set; }
      public string PartNumber{ get; set; }
      public Part(string strID, string strDescFr, string strDescEng, string strPartNumber) 
      {
          this.ID = strID;
          this.DescFr = strDescfr;
          this.DescEng = strDescEng;
          this.PartNumber= strPartNumber;
      }
  }
  </code></pre>
  
  <p>So in another class I use that class to create a list of <code>Part</code> objects via the database.</p>
  
  <pre><code>List&lt;Part&gt; lstParts = DB.Query.GetParts();
  </code></pre>
  
  <p>After that I'm grouping them by description</p>
  
  <pre><code>var lstGrouped = lstParts.GroupBy(x =&gt; x.DescrFr);
  </code></pre>
  
  <p>EDIT:</p>
  
  <pre><code>var lstGrouped = lstParts.GroupBy(x =&gt; x.PartNumber);
  </code></pre>
  
  <p>How can I convert back the <code>lstGrouped</code> back to <code>List&lt;Part&gt;</code>?
  I have tried the <code>ToList()</code> method and cast it to <code>List&lt;Part&gt;</code>, it does not work, giving me an cast error:</p>
  
  <blockquote>
    <p>enable to cast object of type</p>
  </blockquote>