public void Populate(ReferenceDataRoot referenceDataRoot, IValidationContext validationContext)
        {
            var externalDataCache = (ExternalDataCache)_externalDataCache;

            externalDataCache.Standards          = _larsDataMapper.MapLarsStandards(referenceDataRoot.LARSStandards);
            externalDataCache.StandardValidities = _larsDataMapper.MapLarsStandardValidities(referenceDataRoot.LARSStandards);
            externalDataCache.LearningDeliveries = _larsDataMapper.MapLarsLearningDeliveries(referenceDataRoot.LARSLearningDeliveries);

            externalDataCache.ULNs = _ulnDataMapper.MapUlns(referenceDataRoot.ULNs);

            externalDataCache.Postcodes         = _postcodesDataMapper.MapPostcodes(referenceDataRoot.Postcodes);
            externalDataCache.ONSPostcodes      = _postcodesDataMapper.MapONSPostcodes(referenceDataRoot.Postcodes);
            externalDataCache.DevolvedPostcodes = _postcodesDataMapper.MapDevolvedPostcodes(referenceDataRoot.DevolvedPostcodes?.Postcodes);

            externalDataCache.Organisations     = _organisationsDataMapper.MapOrganisations(referenceDataRoot.Organisations);
            externalDataCache.CampusIdentifiers = _organisationsDataMapper.MapCampusIdentifiers(referenceDataRoot.Organisations);

            externalDataCache.EPAOrganisations = _epaOrgDataMapper.MapEpaOrganisations(referenceDataRoot.EPAOrganisations);

            externalDataCache.FCSContractAllocations = _fcsDataMapper.MapFcsContractAllocations(referenceDataRoot.FCSContractAllocations);

            externalDataCache.ERNs = _employersDataMapper.MapEmployers(referenceDataRoot.Employers);

            externalDataCache.ValidationErrors = _validationErrorsDataMapper.MapValidationErrors(referenceDataRoot.MetaDatas?.ValidationErrors);
            externalDataCache.ValidationRules  = _validationRulesDataMapper.MapValidationRules(referenceDataRoot.MetaDatas?.ValidationRules);

            externalDataCache.ReturnPeriod = validationContext.ReturnPeriod;
        }