'Implement L{IKnownHostEntry.toString} by recording the comma-separated
hostnames, key type, and base-64 encoded key.
@return: The string representation of this entry, with unhashed hostname
information.
@rtype: L{bytes}'

def toString(self):

    fields = [','.join(self._hostnames), self.keyType, _b64encode(self.publicKey.blob())]
    if (self.comment is not None):
        fields.append(self.comment)
    return '    '.join(fields)
