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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def gatherkeys_missing(args, distro, rlogger, keypath, keytype, dest_dir):
 """ Get or create the keyring from the mon using the mon keyring by keytype and copy to dest_dir """

    args_prefix = [
        '/usr/bin/ceph',
        '--connect-timeout=25',
        '--cluster={cluster}'.format(
            cluster=args.cluster),
        '--name', 'mon.',
        '--keyring={keypath}'.format(
            keypath=keypath),
        ]

    identity = keytype_identity(keytype)
    if identity is None:
        raise RuntimeError('Could not find identity for keytype:%s' % keytype)
    capabilites = keytype_capabilities(keytype)
    if capabilites is None:
        raise RuntimeError('Could not find capabilites for keytype:%s' % keytype)

    # First try getting the key if it already exists, to handle the case where
    # it exists but doesn't match the caps we would pass into get-or-create.
    # This is the same behvaior as in newer ceph-create-keys
    out, err, code = remoto.process.check(
        distro.conn,
        args_prefix + ['auth', 'get', identity]
        )
    if code == errno.ENOENT:
        out, err, code = remoto.process.check(
            distro.conn,
            args_prefix + ['auth', 'get-or-create', identity] + capabilites
            )
    if code != 0:
        rlogger.error(
            '"ceph auth get-or-create for keytype %s returned %s',
            keytype, code
        )
        for line in err:
            rlogger.debug(line)
        return False
    keyring_name_local = keytype_path_to(args, keytype)
    keyring_path_local = os.path.join(dest_dir, keyring_name_local)
    with open(keyring_path_local, 'wb') as f:
        for line in out:
            f.write(line + b'\n')
    return True