title: IEnumerable - implementing using GetEnumerator from local variable
body: <p>I'm newb with generics/iterators/enumerators etc.</p>
  
  <p>I have code, it keeps field number (int) and error mesages (List string) for each field:</p>
  
  <pre><code>  public class ErrorList : IEnumerable // ?
    {
          private Dictionary &lt;int, List&lt;string&gt;&gt; errorList;
  
          // ...
    }
  </code></pre>
  
  <p>How to make this class work with foreach loop? I wanna use GetEnumerator form Dictionary, but how should i do this?</p>