title: how to write in properties file without deleting old values
body: <p>I want to write in properties file without removing earlier written values in file.
  for Eg there is value in properties file</p>
  
  <pre><code>token = tokengenerated
  </code></pre>
  
  <p>Now when I again set new value like</p>
  
  <pre><code>token1 = tokensnew
  </code></pre>
  
  <p>Then the properties file should show</p>
  
  <pre><code>token = tokengenerated
  token1 = tokensnew 
  </code></pre>