'Used by StartTLSCommand to put us into the state where we don\'t
actually send things that get sent, instead we buffer them.  see
L{_sendBoxCommand}.'

def _prepareTLS(self, certificate, verifyAuthorities):

    self._startingTLSBuffer = []
    if (self.hostCertificate is not None):
        raise OnlyOneTLS(('Previously    authenticated    connection    between    %s    and    %s    is    trying    to    re-establish    as    %s' % (self.hostCertificate, self.peerCertificate, (certificate, verifyAuthorities))))
