code: def get_logged_in_by(self, login, parent_zc, duration=0):
          
          domain_name = zobjects.Account(name=login).get_domain()
          preauth_key = parent_zc.get_domain(domain_name)['zimbraPreAuthKey']
  
          rc = self.REST_PREAUTH(
              self._server_host, parent_zc._server_port, preauth_key=preauth_key)
  
          authToken = rc.get_preauth_token(login)
  
          self.login_with_authToken(authToken)
docs: Use another client to get logged in via preauth mechanism by an
          already logged in admin.
  
          It required the domain of the admin user to have preAuthKey
          The preauth key cannot be created by API, do it with zmprov :
              zmprov gdpak <domain>