title: Join two list on a specified column
body: <p>I am attempting to join two lists (flist and slist) on the ID column. List definitions, class definitions, list contents, and desired results are displayed below.</p>
  
  <pre><code>List&lt;first&gt; flist= new List&lt;first&gt;();
  List&lt;second&gt; slist= new List&lt;second&gt;();
  
  
  public class first
  {
     public string name { get; set; }
     public int ID{ get; set; }
     public string itemAttr { get; set; }
  }
  public class second
  {
     public int ID{ get; set; }
     public string itemAttr{ get; set; }
  }
  </code></pre>
  
  <p>List contents</p>
  
  <pre><code>flist:
  apples | 1
  bananas| 2
  trees  | 3
  
  slist:
  1      | fruit
  3      | not-fruit
  </code></pre>
  
  <p>Desired result:</p>
  
  <pre><code>flist:
  apples   |   1     | fruit
  bananas  |   2     |
  trees    |   3     | not-fruit
  </code></pre>