Implicitly constructed BaseGraphRequestAdapter can't be disposed

[NickDarvey]

Is your feature request related to a problem? Please describe.
Two constructors of Microsoft.Graph.GraphServiceClient ¹ create instances of Microsoft.Graph.BaseGraphRequestAdapter. Microsoft.Graph.BaseGraphRequestAdapter needs to be disposed because it inherits ² from Microsoft.Kiota.Http.HttpClientLibrary.HttpClientRequestAdapter which needs to dispose its System.Net.HttpClient ³.

Describe the solution you'd like
Microsoft.Kiota.Http.HttpClientLibrary.HttpClientRequestAdapter is disposable, therefore Microsoft.Graph.BaseGraphRequestAdapter which inherits from the former is disposable, therefore Microsoft.Graph.GraphServiceClient which instantiates the former should be disposable, following the cascading disposable pattern ⁴.

Describe alternatives you've considered
Alternatively, the GraphServiceClient constructor overloads that implicitly create a BaseGraphRequestAdapter could be obsoleted, forcing the user to instantiate BaseGraphRequestAdapter and dispose of it directly.

Additional context
A workaround is to use the GraphServiceClient constructor overloads that accept a BaseGraphRequestAdapter, instantiating and disposing the BaseGraphRequestAdapter yourself.

Footnotes

1. https://github.com/microsoftgraph/msgraph-sdk-dotnet/blob/82d4f5d4b7a8216e787f2b227e08019773f6cc02/src/Microsoft.Graph/GraphServiceClient.cs#L59-L78 ↩

2. https://github.com/microsoftgraph/msgraph-sdk-dotnet-core/blob/3708629f91bc314a30d07e349cf6205f8ed30b52/src/Microsoft.Graph.Core/Requests/BaseGraphRequestAdapter.cs#LL16C68-L16C68 ↩

3. https://github.com/microsoft/kiota-http-dotnet/blob/58fb5f4ad6edbaf54dfe184fa2d3b8538bc558f2/src/HttpClientRequestAdapter.cs#L530-L538 ↩

4. https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/implementing-dispose#cascade-dispose-calls ↩

[andrueastman]

Thanks for raising this @NickDarvey

Just to add here. Another alternative would be to probably do something like this.

if (graphClient.RequestAdapter is IDisposable disposable)
{
    disposable. Dispose();
}