code: def delegate_auth(self, account):
          
          warnings.warn("delegate_auth() on parent client is deprecated,"
                        " use delegated_login() on child client instead",
                        DeprecationWarning)
          selector = account.to_selector()
          resp = self.request('DelegateAuth', {'account': selector})
  
          lifetime = resp['lifetime']
          authToken = resp['authToken']
  
          zc = ZimbraAccountClient(self._server_host)
          zc.login_with_authToken(authToken, lifetime)
          return zc
docs: Uses the DelegateAuthRequest to provide a ZimbraAccountClient
          already logged with the provided account.
  
          It's the mechanism used with the "view email" button in admin console.