CommandHistoryWindow.cs

[Import]
private IDbgToolWindowManager _toolWindowManager;

public CommandHistoryWindow()
{
    History = new ObservableCollection<Tuple<string, string>>();
    OpenCommand = new DelegateCommand<string>(Open);
}

public DelegateCommand<string> OpenCommand { get; }

private void Open(string commandOutput)
{
    _toolWindowManager.OpenToolWindow("CommandWindow", commandOutput);
}