def to_line(self):
if self.valid:<EOL><INDENT>return '<STR_LIT>' % ('<STR_LIT:U+002C>'.join(self.hostnames), self.key.get_name(),<EOL>self.key.get_base64())<EOL><DEDENT>return None<EOL>
Returns a string in OpenSSH known_hosts file format, or None if
the object is not in a valid state.  A trailing newline is
included.