MVVM: Unit testing Relay Command that fires an async void function

In my view model, I have a relay command that executes an async void method like this:

public ICommand MyCommand=new DelegateCommand(DoSomething, CanDoSomething);

 private async void DoSomething(object parameter)
        {
            await AsyncMethod1();
            await AsyncMethod2();
        }

How can I unit test the execution of the command, knowing that AsyncMethod1 and AsyncMethod2 are private.