def test_printFingerprint(self):
        """
        L{printFingerprint} writes a line to standard out giving the number of
        bits of the key, its fingerprint, and the basename of the file from it
        was read.
        """
        filename = self.mktemp()
        FilePath(filename).setContent(publicRSA_openssh)
        printFingerprint({'filename': filename,
            'format': 'md5-hex'})
        self.assertEqual(
            self.stdout.getvalue(),
            '2048 85:25:04:32:58:55:96:9f:57:ee:fb:a8:1a:ea:69:da temp\n')

        L{printFingerprint} writes a line to standard out giving the number of
        bits of the key, its fingerprint, and the basename of the file from it
        was read.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_ckeygen.py