code: def normalize(self):
          
          if self.has_egg_file():
              if self.has_zip():
                  self.__remove_zip()
          else:
              if self.has_egg_folder():
                  if not self.has_zip():
                      self.__zip_egg_folder()
                  self.__remove_egg_folder()
              self.__rename_zip_to_egg()
docs: Makes sure this egg distribution is stored only as an egg file.
  
          The egg file will be created from another existing distribution format
          if needed.