parameters: (self, user_id, country_code)
return_statement: return self.get_queryset().filter(country=country_code).filter(
              Q(owner__isnull=True) | Q(owner__id=user_id)).filter(number__startswith='+').filter(
              last_connection__gte=timezone.now() - timedelta(minutes=15))
docstring: @param user_id: ID of the user to list phones for
          @type user_id: int
          @param country_code: Country code to filter phones
          @type country_code: str
          @return: List of phones belonging to country and given user, active during last 15 minutes
          @rtype: QuerySet of PhoneData
function: def get_active_phones(self, user_id, country_code):
          """
          @param user_id: ID of the user to list phones for
          @type user_id: int
          @param country_code: Country code to filter phones
          @type country_code: str
          @return: List of phones belonging to country and given user, active during last 15 minutes
          @rtype: QuerySet of PhoneData
          """
          return self.get_queryset().filter(country=country_code).filter(
              Q(owner__isnull=True) | Q(owner__id=user_id)).filter(number__startswith='+').filter(
              last_connection__gte=timezone.now() - timedelta(minutes=15))
function_tokens: def get_active_phones ( self , user_id , country_code ) : return self . get_queryset ( ) . filter ( country = country_code ) . filter ( Q ( owner__isnull = True ) | Q ( owner__id = user_id ) ) . filter ( number__startswith = '+' ) . filter ( last_connection__gte = timezone . now ( ) - timedelta ( minutes = 15 ) )