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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def send_activation_email(self):
 """ Sends a activation email to the user. This email is send when the user wants to activate their newly created user. """

        context= {'user': self,
                  'protocol': get_protocol(),
                  'activation_days': defaults.ACCOUNTS_ACTIVATION_DAYS,
                  'activation_key': self.activation_key,
                  'site': Site.objects.get_current()}

        subject = ''.join(render_to_string(
                    'accounts/emails/activation_email_subject.txt',
                    context).splitlines())

        message = render_to_string(
                    'accounts/emails/activation_email_message.txt',
                    context)
        send_mail(subject,
                  message,
                  settings.DEFAULT_FROM_EMAIL,
                  [self.email,])