code: def import_ownertrust(cls, trustdb=None):
      
      if trustdb is None:
          trustdb = os.path.join(cls.homedir, 'trustdb.gpg')
  
      import_proc = cls._open_subprocess(['--import-ownertrust'])
  
      try:
          tdb = open(trustdb, 'rb')
      except (OSError, IOError):
          log.error("trustdb file %s does not exist!" % trustdb)
  
      _util._threaded_copy_data(tdb, import_proc.stdin)
      import_proc.wait()
docs: Import ownertrust from a trustdb file.
  
      :param str trustdb: The path to the trustdb.gpg file. If not given,
                          defaults to :file:`trustdb.gpg` in the current GnuPG
                          homedir.