code: def hyphen(self):
          '''
          Returns ISBN number with segment hypenation
          Data obtained from https://www.isbn-international.org/
          https://www.isbn-international.org/export_rangemessage.xml
          @return: ISBN formated as ISBN13 with hyphens
          '''
          if not ISBN.hyphenRange:
              ISBN.hyphenRange = hyphen.ISBNRange()
  
          return ISBN.hyphenRange.hyphenformat(self._idf hyphen(self):
          '''
          Returns ISBN number with segment hypenation
          Data obtained from https://www.isbn-international.org/
          https://www.isbn-international.org/export_rangemessage.xml
          @return: ISBN formated as ISBN13 with hyphens
          '''
          if not ISBN.hyphenRange:
              ISBN.hyphenRange = hyphen.ISBNRange()
  
          return ISBN.hyphenRange.hyphenformat(self._id)
docs: Returns ISBN number with segment hypenation
          Data obtained from https://www.isbn-international.org/
          https://www.isbn-international.org/export_rangemessage.xml
          @return: ISBN formated as ISBN13 with hyphens