def listen(self, port=None, host='', backlog=1024):
"""
Begins listening on the given host and port.
Args:
port: The port to listen on. Optional. If not specified, will be
set to 80 for regular HTTP, or 443 if SSL options have been
set.
host: The hostname to listen on. Defaults to ''.
backlog: The maximum number of queued connections. Defaults
to 1024.
"""
if not port:
if self.ssl_options:
port = 443
else:
port = 80
SSLServer.listen(self, port, host, backlog)
