private void PassCoverImageFromFB2(CoverPage coverPage, EPubFileV2 epubFile)
 {
     // if we have at least one coverpage image
     if ((coverPage != null) && (coverPage.HasImages()) && (coverPage.CoverpageImages[0].HRef != null))
     {
         // we add just first one 
         var coverPageFile = new CoverPageFileV2(coverPage.CoverpageImages[0], _referencesManager);
         epubFile.AddXHTMLFile(coverPageFile);
         Images.ImageIdUsed(coverPage.CoverpageImages[0].HRef);
         epubFile.SetCoverImageID(coverPage.CoverpageImages[0].HRef);
     }
 }