code: def add_alternate_formats(self, filename):
          
          with open(filename, "r") as infile:
              xtree = etree.parse(infile)
          self.alt_territory = {}  # country_code to XAlternateTerritory
          xterritories = xtree.find(TOP_XPATH)
          for xterritory in xterritories:
              if xterritory.tag == TERRITORY_TAG:
                  terrobj = XAlternateTerritory(xterritory)
                  id = str(terrobj.country_code)
                  if id in self.alt_territory:
                      raise Exception("Duplicate entry for %s" % id)
                  self.alt_territory[id] = terrobj
              else:
                  raise Exception("Unexpected element %s found" % xterritory.tag)
docs: Add phone number alternate format metadata retrieved from XML