title: How to sort a string's characters alphabetically?
body: <p>For Array, there is a pretty <code>sort</code> method to rearrange the sequence of elements. I want to achieve the same results for a String.</p>
  
  <p>For example, I have a string <code>str = "String"</code>, I want to sort it alphabetically with one simple method to <code>"ginrSt"</code>.</p>
  
  <p>Is there a native way to enable this or should I include mixins from <code>Enumerable</code>?</p>