title: How would I distinct my list of key/value pairs
body: <p>If I have a list <code>List&lt;KeyValuePair&lt;string,string&gt;&gt;</code>ex. </p>
  
  <pre><code>["abc","123"]
  ["asc","123"]
  ["asdgf","123"]
  ["abc","123"]
  </code></pre>
  
  <p>how can I distinc this list?</p>