code: def country_name_for_number(numobj, lang, script=None, region=None):
      
      region_codes = region_codes_for_country_code(numobj.country_code)
      if len(region_codes) == 1:
          return _region_display_name(region_codes[0], lang, script, region)
      else:
          region_where_number_is_valid = u("ZZ")
          for region_code in region_codes:
              if is_valid_number_for_region(numobj, region_code):
                  # If the number has already been found valid for one region,
                  # then we don't know which region it belongs to so we return
                  # nothing.
                  if region_where_number_is_valid != u("ZZ"):
                      return U_EMPTY_STRING
                  region_where_number_is_valid = region_code
          return _region_display_name(region_where_number_is_valid, lang, script, region)
docs: Returns the customary display name in the given langauge for the given
      territory the given PhoneNumber object is from.  If it could be from many
      territories, nothing is returned.
  
      Arguments:
      numobj -- The PhoneNumber object for which we want to get a text description.
      lang -- A 2-letter lowercase ISO 639-1 language code for the language in
                    which the description should be returned (e.g. "en")
      script -- A 4-letter titlecase (first letter uppercase, rest lowercase)
                    ISO script code as defined in ISO 15924, separated by an
                    underscore (e.g. "Hant")
      region --  A 2-letter uppercase ISO 3166-1 country code (e.g. "GB")
  
      The script and region parameters are currently ignored.
  
      Returns a text description in the given language code, for the given phone
      number's region, or an empty string if no description is available.