title: Checking for an array in a list, with "List<int[]>.Contains(new int[] { .. })", always returns false
body: <p>I am trying to check if list that consists of int[2] arrays contains certain element.</p>
  
  <p>In short, why this produces false?
  And how can I check this properly?</p>
  
  <pre><code>List &lt; int[] &gt; ngonPairs = new List&lt;int[]&gt; {new int[2] { 0, 1 }};
  
  bool flag = ngonPairs.Contains(new int[2] { 0, 1 });
  </code></pre>
  
  <p>Flag is always false.</p>