code: def add_missing_xml_attributes(dom, volume_counter=0):
      
      mods_tag = get_mods_tag(dom)
  
      if mods_tag:
          params = mods_tag.params
  
          # add missing attributes
          params["ID"] = "MODS_VOLUME_%04d" % (volume_counter + 1)
          params["xmlns:mods"] = "http://www.loc.gov/mods/v3"
          params["xmlns:xlink"] = "http://www.w3.org/1999/xlink"
          params["xmlns:xsi"] = "http://www.w3.org/2001/XMLSchema-instance"
          params["xsi:schemaLocation"] = " ".join((
              "http://www.w3.org/2001/XMLSchema-instance",
              "http://www.w3.org/2001/XMLSchema.xsd",
              "http://www.loc.gov/mods/v3",
              "http://www.loc.gov/standards/mods/v3/mods-3-4.xsd",
              "http://www.w3.org/1999/xlink http://www.w3.org/1999/xlink.xsd",
          ))
docs: Add `xmlns` and `ID` attributes to ``<mods:mods>`` tag.
  
      Args:
          dom (HTMLElement): DOM containing whole document.
          volume_counter (int, default 0): ID of volume.