public void LogModificationToText(Guid textId)
 {
     if (TextRepository.Exists(textId))
     {
         Text    textOfModdedDocument    = TextRepository.GetById(textId);
         Content contentOfModdedDocument = textOfModdedDocument.ContentThatBelongs;
         if (HeaderRepository.ExistsWithContent(contentOfModdedDocument))
         {
             Header headerOfModdedDocument = HeaderRepository.GetByContent(contentOfModdedDocument);
             LogModificationToDocument(headerOfModdedDocument.DocumentThatBelongs.Id);
         }
         else if (ParagraphRepository.ExistsWithContent(contentOfModdedDocument))
         {
             Paragraph paragraphOfModdedDocument = ParagraphRepository.GetByContent(contentOfModdedDocument);
             LogModificationToDocument(paragraphOfModdedDocument.DocumentThatBelongs.Id);
         }
         else if (FooterRepository.ExistsWithContent(contentOfModdedDocument))
         {
             Footer footerOfModdedDocument = FooterRepository.GetByContent(contentOfModdedDocument);
             LogModificationToDocument(footerOfModdedDocument.DocumentThatBelongs.Id);
         }
     }
     else
     {
         throw new MissingTextException("This text is not in the database.");
     }
 }