title: Split a string after each two characters
body: <p>I want to split a string after each two characters. </p>
  
  <p>For Example:</p>
  
  <pre><code>String aString= "abcdef"
  </code></pre>
  
  <p>I want to have after a split <code>"ab cd ef"</code></p>
  
  <p>How can i do it?</p>
  
  <p>Thanks :)</p>