title: Method's parameter 'self' reassigned
body: <p>Is it possible to reassign self inside its own class?</p>
  
  <p>I have a form for that class which have <code>okay</code> button and <code>cancel</code> button. If the user click <code>okay</code>, I will only pass its value to another window. However, if I click <code>cancel</code>, I want to return the state of that form to its previous state. So if the user click that form and it contains value, then the user add a field, but he/she decided to click cancel, I want to reassign the previous state of the instance.</p>