title: Add elements from IList to ObservableCollection
body: <p>I have an ObservableCollection, and I'd like to set the content of an IList to this one. Now I could just create a new instance of the collection..: </p>
  
  <pre><code>public ObservableCollection&lt;Bar&gt; obs = new ObservableCollection&lt;Bar&gt;(); 
  public void Foo(IList&lt;Bar&gt; list)
  {
      obs = new ObservableCollection&lt;Bar&gt;(list); 
  }
  </code></pre>
  
  <p>But how can I actually take the content of the IList and add it to my existing ObservableCollection? Do I have to loop over all elements, or is there a better way? </p>
  
  <pre><code>public void Foo(IList&lt;Bar&gt; list)
  {
     foreach (var elm in list)
         obs.Add(elm); 
  }
  </code></pre>