Multiple Web Pages and Ribbon in SharePoint

I am linking a feed to my web part. I need to add more than two web pages per page.

I do not want to have a separate contextual group / tab for each web part. Is there a way to check if a specific group / tab exists in the current feed on the page?

At this point, when I add more than one web page to a page, I get the following error:

Item has already been added. Key in dictionary: 'Ribbon.MyContextualTabGroup' Key being added: 'Ribbon.MyContextualTabGroup'

Here is my code for your reference:

/// <summary>
/// Gets the web part contextual info.
/// </summary>
public WebPartContextualInfo WebPartContextualInfo
{
    get
    {
        var webPartContextualInfo = new WebPartContextualInfo();
        var webPartRibbonContextualGroup = new WebPartRibbonContextualGroup();
        var webPartRibbonTab = new WebPartRibbonTab();

        webPartRibbonContextualGroup.Id = "Ribbon.MyContextualTabGroup";
        webPartRibbonContextualGroup.Command = "MyContextualTab.EnableContextualGroup";
        webPartRibbonContextualGroup.VisibilityContext = "MyContextualTab.CustomVisibilityContext";

        webPartRibbonTab.Id = "Ribbon.MyTab";
        webPartRibbonTab.VisibilityContext = "MyContextualTab.CustomVisibilityContext";

        webPartContextualInfo.ContextualGroups.Add(webPartRibbonContextualGroup);
        webPartContextualInfo.Tabs.Add(webPartRibbonTab);
        webPartContextualInfo.PageComponentId = SPRibbon.GetWebPartPageComponentId(this);

        return webPartContextualInfo;
    }
}

/// <summary>
/// Adds the contextual tab.
/// </summary>
private void AddContextualTab()
{
    SPRibbon spRibbon = SPRibbon.GetCurrent(Page);

    if (spRibbon == null) return;

    var ribbonExtensions = new XmlDocument();

    ribbonExtensions.LoadXml(_contextualTab);
    spRibbon.RegisterDataExtension(ribbonExtensions.FirstChild, "Ribbon.ContextualTabs._children");

    ribbonExtensions.LoadXml(_contextualTabTemplate);
    spRibbon.RegisterDataExtension(ribbonExtensions.FirstChild, "Ribbon.Templates._children");
}

/// <summary>
/// The event handler for the System.Web.UI.Control.PreRender event that occurs immediately before the Web Part is rendered to the Web Part Page it is contained on.
/// </summary>
/// <param name="e">A System.EventArgs that contains the event data.</param>
protected override void OnPreRender(EventArgs e)
{
    base.OnPreRender(e);

    AddContextualTab();

    ClientScriptManager clientScriptManager = Page.ClientScript;
    clientScriptManager.RegisterClientScriptBlock(GetType(), "MyWebPart", DelayScript);
}