def __init__(self, **kw):
        """
        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.
        """
        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)

        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.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/protocols/amp.py