private static ApplicationPartManager GetApplicationPartManager(IServiceCollection services, IWebHostEnvironment?environment) { var manager = GetServiceFromCollection <ApplicationPartManager>(services); if (manager == null) { manager = new ApplicationPartManager(); var entryAssemblyName = environment?.ApplicationName; if (string.IsNullOrEmpty(entryAssemblyName)) { return(manager); } manager.PopulateDefaultParts(entryAssemblyName); } return(manager); }