public void Reload(ISiteDataProvider provider)
 {
     new SitesXmlLoader(provider).Load(provider.LoadXmlData(), ref sitesModel);
     if (sitesModel != null)
     {
         provider.SaveDataToLocal(sitesModel);
     }
 }
        public SitesProvider(ISiteDataProvider provider)
        {
            var data = provider.LoadDataLocal();

            if (data == null)
            {
                new SitesXmlLoader(provider).Load(provider.LoadXmlData(), ref sitesModel);
                if (sitesModel != null)
                {
                    provider.SaveDataToLocal(sitesModel);
                }
            }
            else
            {
                sitesModel = data;
            }
        }