code: def send_activation_email(self, user):
          
          activation_key = self.get_activation_key(user)
          context = self.get_email_context(activation_key)
          context['user'] = user
          subject = render_to_string(
              template_name=self.email_subject_template,
              context=context,
              request=self.request
          )
          # Force subject to a single line to avoid header-injection
          # issues.
          subject = ''.join(subject.splitlines())
          message = render_to_string(
              template_name=self.email_body_template,
              context=context,
              request=self.request
          )
          user.email_user(subject, message, settings.DEFAULT_FROM_EMAIL)
docs: Send the activation email. The activation key is the username,
          signed using TimestampSigner.