when `ProviderManager.SaveMetadata` gets called before
`ProviderManager.AddParts`
```
Error Message:
System.ArgumentNullException : Value cannot be null. (Parameter 'source')
Stack Trace:
at System.Linq.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
at System.Linq.Enumerable.Where[TSource](IEnumerable`1 source, Func`2 predicate)
at MediaBrowser.Providers.Manager.ProviderManager.SaveMetadata(BaseItem item, ItemUpdateType updateType, IEnumerable`1 savers) in D:\a\1\s\MediaBrowser.Providers\Manager\ProviderManager.cs:line 674
at MediaBrowser.Providers.Manager.ProviderManager.SaveMetadata(BaseItem item, ItemUpdateType updateType) in D:\a\1\s\MediaBrowser.Providers\Manager\ProviderManager.cs:line 655
at Emby.Server.Implementations.Library.LibraryManager.RunMetadataSavers(BaseItem item, ItemUpdateType updateReason) in D:\a\1\s\Emby.Server.Implementations\Library\LibraryManager.cs:line 2012
at Emby.Server.Implementations.Library.LibraryManager.UpdateItemsAsync(IReadOnlyList`1 items, BaseItem parent, ItemUpdateType updateReason, CancellationToken cancellationToken) in D:\a\1\s\Emby.Server.Implementations\Library\LibraryManager.cs:line 1970
at Emby.Server.Implementations.Library.LibraryManager.CreateRootFolder() in D:\a\1\s\Emby.Server.Implementations\Library\LibraryManager.cs:line 775
at Emby.Server.Implementations.Library.LibraryManager.get_RootFolder() in D:\a\1\s\Emby.Server.Implementations\Library\LibraryManager.cs:line 180
at Emby.Server.Implementations.IO.LibraryMonitor.Start() in D:\a\1\s\Emby.Server.Implementations\IO\LibraryMonitor.cs:line 135
at Emby.Server.Implementations.IO.LibraryMonitorStartup.RunAsync() in D:\a\1\s\Emby.Server.Implementations\IO\LibraryMonitorStartup.cs:line 26
at Emby.Server.Implementations.ApplicationHost.StartEntryPoints(IEnumerable`1 entryPoints, Boolean isBeforeStartup)+MoveNext() in D:\a\1\s\Emby.Server.Implementations\ApplicationHost.cs:line 541
at System.Threading.Tasks.Task.WhenAll(IEnumerable`1 tasks)
at Emby.Server.Implementations.ApplicationHost.RunStartupTasksAsync(CancellationToken cancellationToken) in D:\a\1\s\Emby.Server.Implementations\ApplicationHost.cs:line 525
at Jellyfin.Server.Integration.Tests.JellyfinApplicationFactory.CreateServer(IWebHostBuilder builder) in D:\a\1\s\tests\Jellyfin.Server.Integration.Tests\JellyfinApplicationFactory.cs:line 101
at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.EnsureServer()
at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.CreateDefaultClient(DelegatingHandler[] handlers)
at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.CreateDefaultClient(Uri baseAddress, DelegatingHandler[] handlers)
at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.CreateClient(WebApplicationFactoryClientOptions options)
at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.CreateClient()
at Jellyfin.Server.Integration.Tests.OpenApiSpecTests.GetSpec_ReturnsCorrectResponse() in D:\a\1\s\tests\Jellyfin.Server.Integration.Tests\OpenApiSpecTests.cs:line 26
--- End of stack trace from previous location ---
```
Bond_009
cvium
David
Gary Wilber
Erwin de Haan
Patrick Barron
Patrick Barron
crobibero
Mark Monteiro
telans
Luke Foust
dkanada
Joshua M. Boniface
hawken
Andrew Rabert
stefan
Luke Pulverenti
softworkz
Eric Reed