code: def add_genre(dom):
      
      mods_tag = get_mods_tag(dom)
  
      matched_genres = [
          "electronic title",
          "electronic volume",
      ]
      genre = dom.find(
          "mods:genre",
          fn=lambda x: x.getContent().lower().strip() in matched_genres
      )
  
      if not genre:
          genre_tag = dhtmlparser.HTMLElement(
              "mods:genre",
              [dhtmlparser.HTMLElement("electronic volume")]
          )
          insert_tag(genre_tag, dom.find("mods:originInfo"), mods_tag)
docs: Add ``<mods:genre>`` with `electronic volume` content into
      ``<mods:originInfo``.