SignalR - how to create mock Hub Groups when testing?

Question

ASP.NET

Please tell me how to create mock Hub Groups when testing. Specifically for the current version of SIgnalR. And then there are no examples or documentation on testing the new SignalR on the network. And the docks for the old version are not relevant. For example, in the old version of https://docs.microsoft.com/en-us/aspnet/signalr/ov... , when creating mock clients, the IHubCallerConnectionContext interface is used, while in the current version it does not exist at all.