title: Django ModelForm: How to override or check for "save_as"
body: <p>I need to add some customizations for the case that a instance in Django Admin is "saved_as" a copy. Can I do that in <code>save()</code>, if so how do I check for the <code>save_as kwarg</code>?
  Or is there a <code>save_as()</code> method I can override somewhere. I was not able to find any information about the differences in the process between a regular <code>save()</code> and one with <code>save_as = True</code>.</p>
  
  <p>Can someone point me to an example or give me an hint where to go?</p>
  
  <p>Thank you very much for your time!</p>
  
  <p>:)</p>