sample.cs

public static ChannelReader<T> CreateScheduleMessenger<T>(ChannelReader<T> channelReader,
    Command command)
 {
     var output = Channel.CreateUnbounded<T>();

     Task.Run(async () =>
     {

         if (command is Command.Get)
         {
                 var raw = await channelReader.ReadAsync();
                 OmaObject omaObject = (OmaObject)Convert.ChangeType(raw, typeof(OmaObject));

                 var hash = $"{omaObject.Customer}{omaObject.Device}{omaObject.TestName}";
                 if (!State.ContainsKey(hash))
                     State.Add(hash, omaObject);

                 Console.WriteLine($"Schedule state count: {State.Count}");
                 await output.Writer.WriteAsync((T)omaObject);


         } else if (command is Command.Delete)
         {
                 var omaObject = await channelReader.ReadAsync();
                 State.Clear();
                 Console.WriteLine($"State has been cleaned: {State.Count}");

                 await output.Writer.WriteAsync(true);

         }

     });

     output.Writer.Complete();

     return output;
 }

Of course this doesn't compile.