code: def from_comm(cls, pub):
          '''
          Convert communication namedtuple to this class.
  
          Args:
              pub (obj): :class:`.Archive` instance which will be converted.
  
          Returns:
              obj: :class:`DBArchive` instance.
          '''
          filename = None
          if pub.b64_data:
              filename = cls._save_to_unique_filename(pub)
  
          return cls(
              isbn=pub.isbn,
              uuid=pub.uuid,
              aleph_id=pub.aleph_id,
  
              dir_pointer=filename
          f from_comm(cls, pub):
          '''
          Convert communication namedtuple to this class.
  
          Args:
              pub (obj): :class:`.Archive` instance which will be converted.
  
          Returns:
              obj: :class:`DBArchive` instance.
          '''
          filename = None
          if pub.b64_data:
              filename = cls._save_to_unique_filename(pub)
  
          return cls(
              isbn=pub.isbn,
              uuid=pub.uuid,
              aleph_id=pub.aleph_id,
  
              dir_pointer=filename
          )
docs: Convert communication namedtuple to this class.
  
          Args:
              pub (obj): :class:`.Archive` instance which will be converted.
  
          Returns:
              obj: :class:`DBArchive` instance.