title: How to generate Api key for my app
body: <p>I want to generate api key. There are some ways to generate random string. But I am afraid of duplicate random string generation. For example: if I generate 3 random string and as :</p>
  
  <pre><code>absd322e332
  fsdafa232da
  absd322e332
  </code></pre>
  
  <p>Here first one and last one is equal. But I have to be over sure that there is no duplicate random string. How can I achieve this. Any help is appreciated.</p>