code: def update(self, request, key):
          
  
          request.UPDATE = http.QueryDict(request.body)
  
          email_addr = request.UPDATE.get('email')
          user_id = request.UPDATE.get('user')
          if not email_addr:
              return http.HttpResponseBadRequest()
  
          try:
              email = EmailAddress.objects.get(address=email_addr,
                                               user_id=user_id)
          except EmailAddress.DoesNotExist:
              raise http.Http404
  
          email.user.email = email_addr
          email.user.save()
          return http.HttpResponse(status=204)
docs: Set an email address as primary address.