title: How to clone value in angular 5
body: <p>I have a edit form with save and cancel button. When the save will be clicked, the value will be send to server and everything is okey.</p>
  
  <p>But in case server did not able to process the data, I need come back to the revious state of the data.</p>
  
  <p>So is there a way to clone the data and keep it, in case of server error, send it to the UI form for display?</p>