Method hiding in C# classes
<p>I'm looking at <code>LinkedList</code> class implementation in C# and I cannot understand how
Add method is hidden.</p>

<p><code>LinkedList</code> implements <code>ICollection</code> which has an <code>Add</code> method. In the <code>LinkedList</code> class code the <code>Add</code> method is declared as:</p>

<pre><code>void ICollection&lt;T&gt;.Add(T value);
</code></pre>

<p>How it is possible to have internal method which is declared in the interface?</p>
