title: Override save, put, get, etc... methods in Google App Engine
body: <p>Is it possible to override methids for db.Model in Google App Engine?
  I want to declare beforeSave, afterSave methods, etc.. to create automatic tagging system.</p>
  
  <p>I know there are hooks, but it seems to me a wrong way to solve this issue :)</p>
  
  <p>Thanks!</p>