How to use the cheroot.server.Gateway function in cheroot

from cheroot.test import webtest
import cheroot.wsgi

EPHEMERAL_PORT = 0
NO_INTERFACE = None  # Using this or '' will cause an exception
ANY_INTERFACE_IPV4 = '0.0.0.0'
ANY_INTERFACE_IPV6 = '::'

config = {
    cheroot.wsgi.Server: {
        'bind_addr': (NO_INTERFACE, EPHEMERAL_PORT),
        'wsgi_app': None,
    },
    cheroot.server.HTTPServer: {
        'bind_addr': (NO_INTERFACE, EPHEMERAL_PORT),
        'gateway': cheroot.server.Gateway,
    },
}


def cheroot_server(server_factory):
    """Set up and tear down a Cheroot server instance."""
    conf = config[server_factory].copy()
    bind_port = conf.pop('bind_addr')[-1]

    for interface in ANY_INTERFACE_IPV6, ANY_INTERFACE_IPV4:
        try:
            actual_bind_addr = (interface, bind_port)
            httpserver = server_factory(  # create it
                bind_addr=actual_bind_addr,
                **conf
            )

from cheroot.test import webtest
import cheroot.wsgi

EPHEMERAL_PORT = 0
NO_INTERFACE = None  # Using this or '' will cause an exception
ANY_INTERFACE_IPV4 = '0.0.0.0'
ANY_INTERFACE_IPV6 = '::'

config = {
    cheroot.wsgi.Server: {
        'bind_addr': (NO_INTERFACE, EPHEMERAL_PORT),
        'wsgi_app': None,
    },
    cheroot.server.HTTPServer: {
        'bind_addr': (NO_INTERFACE, EPHEMERAL_PORT),
        'gateway': cheroot.server.Gateway,
    },
}


def cheroot_server(server_factory):
    """Set up and tear down a Cheroot server instance."""
    conf = config[server_factory].copy()
    bind_port = conf.pop('bind_addr')[-1]

    for interface in ANY_INTERFACE_IPV6, ANY_INTERFACE_IPV4:
        try:
            actual_bind_addr = (interface, bind_port)
            httpserver = server_factory(  # create it
                bind_addr=actual_bind_addr,
                **conf
            )

"""Native adapter for serving CherryPy via its builtin server."""

import logging
import sys
import io

import cheroot.server

import cherrypy
from cherrypy._cperror import format_exc, bare_error
from cherrypy.lib import httputil


class NativeGateway(cheroot.server.Gateway):
    """Native gateway implementation allowing to bypass WSGI."""

    recursive = False

    def respond(self):
        """Obtain response from CherryPy machinery and then send it."""
        req = self.req
        try:
            # Obtain a Request object from CherryPy
            local = req.server.bind_addr
            local = httputil.Host(local[0], local[1], '')
            remote = req.conn.remote_addr, req.conn.remote_port
            remote = httputil.Host(remote[0], remote[1], '')

            scheme = req.scheme
            sn = cherrypy.tree.script_name(req.uri or '/')

"""Native adapter for serving CherryPy via its builtin server."""

import logging
import sys
import io

import cheroot.server

import cherrypy
from cherrypy._cperror import format_exc, bare_error
from cherrypy.lib import httputil


class NativeGateway(cheroot.server.Gateway):
    """Native gateway implementation allowing to bypass WSGI."""

    recursive = False

    def respond(self):
        """Obtain response from CherryPy machinery and then send it."""
        req = self.req
        try:
            # Obtain a Request object from CherryPy
            local = req.server.bind_addr
            local = httputil.Host(local[0], local[1], '')
            remote = req.conn.remote_addr, req.conn.remote_port
            remote = httputil.Host(remote[0], remote[1], '')

            scheme = req.scheme
            sn = cherrypy.tree.script_name(req.uri or '/')

max=max,
            accepted_queue_size=accepted_queue_size,
            accepted_queue_timeout=accepted_queue_timeout,
        )

    @property
    def numthreads(self):
        """Set minimum number of threads."""
        return self.requests.min

    @numthreads.setter
    def numthreads(self, value):
        self.requests.min = value


class Gateway(server.Gateway):
    """A base class to interface HTTPServer with WSGI."""

    def __init__(self, req):
        """Initialize WSGI Gateway instance with request.

        Args:
            req (HTTPRequest): current HTTP request
        """
        super(Gateway, self).__init__(req)
        self.started_response = False
        self.env = self.get_environ()
        self.remaining_bytes_out = None

    @classmethod
    def gateway_map(cls):
        """Create a mapping of gateways and their versions.

def resolve(cls, full_path):
        """Read WSGI app/Gateway path string and import application module."""
        mod_path, _, app_path = full_path.partition(':')
        app = getattr(import_module(mod_path), app_path or 'application')

        with contextlib.suppress(TypeError):
            if issubclass(app, server.Gateway):
                return GatewayYo(app)

        return cls(app)

def resolve(cls, full_path):
        """Read WSGI app/Gateway path string and import application module."""
        mod_path, _, app_path = full_path.partition(':')
        app = getattr(import_module(mod_path), app_path or 'application')
        # suppress the `TypeError` exception, just in case `app` is not a class
        with suppress(TypeError):
            if issubclass(app, server.Gateway):
                return GatewayYo(app)

        return cls(app)

"""Native adapter for serving CherryPy via its builtin server."""

import logging
import sys
import io

import cheroot.server

import cherrypy
from cherrypy._cperror import format_exc, bare_error
from cherrypy.lib import httputil


class NativeGateway(cheroot.server.Gateway):
    """Native gateway implementation allowing to bypass WSGI."""

    recursive = False

    def respond(self):
        """Obtain response from CherryPy machinery and then send it."""
        req = self.req
        try:
            # Obtain a Request object from CherryPy
            local = req.server.bind_addr
            local = httputil.Host(local[0], local[1], '')
            remote = req.conn.remote_addr, req.conn.remote_port
            remote = httputil.Host(remote[0], remote[1], '')

            scheme = req.scheme
            sn = cherrypy.tree.script_name(req.uri or '/')