title: Getting multiple keys of specified value of a generic Dictionary?
body: <p>It's easy to get the value of a key from a .NET generic Dictionary:</p>
  
  <pre><code>Dictionary&lt;int, string&gt; greek = new Dictionary&lt;int, string&gt;();
  greek.Add(1, "Alpha");
  greek.Add(2, "Beta");
  string secondGreek = greek[2];  // Beta
  </code></pre>
  
  <p>But trying to get the keys given a value is not as straightforward because there could be multiple keys:</p>
  
  <pre><code>int[] betaKeys = greek.WhatDoIPutHere("Beta");  // expecting single 2
  </code></pre>