code: def write_string(self):
          
  
          map_as_str = []
          for name, id_range_set in self.__map.items():
              for id_range in id_range_set:
                  map_as_str.append(
                          name + ':' +
                          str(id_range.first) + ':' +
                          str(id_range.count) + '\n'
                      )
  
          # Remove trailing newline
          if len(map_as_str) > 0:
              map_as_str[-1] = map_as_str[-1][:-1]
  
          return ''.join(map_as_str)
docs: Return a representation of the id map as a string. This string is
          properly formatted to be written in '/etc/subuid' or '/etc/subgid'.