'Serves app on flow, and prevents further handling of the flow.'

def serve(self, app, flow):

    app = wsgi.WSGIAdaptor(app, flow.request.pretty_host, flow.request.port, version.MITMPROXY)
    err = app.serve(flow, flow.client_conn.wfile, **{'mitmproxy.master': ctx.master})
    if err:
        ctx.log.error(('Error    in    wsgi    app.    %s' % err))
        raise exceptions.AddonHalt()
    flow.reply.kill()
