private void ShowToolWindow(object sender, EventArgs e)
        {
            // Get the instance number 0 of this tool window. This window is single instance so this instance
            // is actually the only one.
            // The last flag is set to true so that if the tool window does not exists it will be created.
            var window = FindToolWindow(typeof(TwitterToolWindow), 0, true);
            if ((null == window) || (null == window.Frame))
            {
                throw new NotSupportedException(Resources.CanNotCreateWindow);
            }

            var windowFrame = (IVsWindowFrame)window.Frame;
            Microsoft.VisualStudio.ErrorHandler.ThrowOnFailure(windowFrame.Show());
        }