'Create a StartTLS command.  (This is private.  Use AMP.callRemote.)
@param tls_localCertificate: the PrivateCertificate object to use to
secure the connection.  If it\'s None, or unspecified, an ephemeral DH
key is used instead.
@param tls_verifyAuthorities: a list of Certificate objects which
represent root certificates to verify our peer with.'

def __init__(self, **kw):

    if (ssl is None):
        raise RuntimeError('TLS    not    available.')
    self.certificate = kw.pop('tls_localCertificate', _NoCertificate(True))
    self.authorities = kw.pop('tls_verifyAuthorities', None)
    Command.__init__(self, **kw)
