How to use the gidgethub.sansio.Event.from_http function in gidgethub

async def process(cls, server: ni_abc.ServerHost,
                      request: web.Request, client: aiohttp.ClientSession) -> "Host":
        """Process the pull request."""
        event = sansio.Event.from_http(request.headers,
                                       await request.read(),
                                       secret=server.contrib_secret())
        if event.event == "ping":
            # A ping event; nothing to do.
            # https://developer.github.com/webhooks/#ping-event
            raise ni_abc.ResponseExit(status=http.HTTPStatus.OK)
        elif event.event != "pull_request":
            # Only happens if GitHub is misconfigured to send the wrong events.
            raise TypeError(f"don't know how to handle a {event.event!r} event")
        elif event.data['action'] not in cls._useful_actions:
            raise ni_abc.ResponseExit(status=http.HTTPStatus.NO_CONTENT)
        elif event.data['action'] in {PullRequestEvent.opened.value, PullRequestEvent.synchronize.value}:
            if event.data['action'] == PullRequestEvent.opened.value:
                # GitHub is eventually consistent, so add a delay to wait for
                # the API to digest the new pull request.
                await asyncio.sleep(1)

async def main(request):
    try:
        body = await request.read()

        secret = os.environ.get("GH_SECRET")
        event = sansio.Event.from_http(request.headers, body, secret=secret)
        print("GH delivery ID", event.delivery_id, file=sys.stderr)
        if event.event == "ping":
            return web.Response(status=200)
        oauth_token = os.environ.get("GH_AUTH")
        async with aiohttp.ClientSession() as session:
            gh = gh_aiohttp.GitHubAPI(
                session, "python/cpython", oauth_token=oauth_token, cache=cache
            )
            # Give GitHub some time to reach internal consistency.
            await asyncio.sleep(1)
            await router.dispatch(event, gh)
            try:
                print(
                    f"""\
GH requests remaining: {gh.rate_limit.remaining}/{gh.rate_limit.limit}, \
reset time: {gh.rate_limit.reset_datetime:%b-%d-%Y %H:%M:%S %Z}, \

async def main(request):
    try:
        body = await request.read()
        secret = os.environ.get("GH_SECRET")
        event = sansio.Event.from_http(request.headers, body, secret=secret)
        print('GH delivery ID', event.delivery_id, file=sys.stderr)
        if event.event == "ping":
            return web.Response(status=200)
        oauth_token = os.environ.get("GH_AUTH")
        async with aiohttp.ClientSession() as session:
            gh = gh_aiohttp.GitHubAPI(session, "python/bedevere",
                                      oauth_token=oauth_token,
                                      cache=cache)
            # Give GitHub some time to reach internal consistency.
            await asyncio.sleep(1)
            await router.dispatch(event, gh, session=session)
        try:
            print('GH requests remaining:', gh.rate_limit.remaining)
        except AttributeError:
            pass
        return web.Response(status=200)

async def dispatch(request):
    github = request.app.plugins["github"]
    payload = await request.read()

    try:
        event = Event.from_http(request.headers, payload, secret=github.verify)
        await github.router.dispatch(event, app=request.app)
    except ValidationFailure:
        LOG.debug(
            "Github webhook failed verification: %s, %s", request.headers, payload
        )
        return Response(status=401)
    except Exception as e:
        LOG.exception(e)
        return Response(status=500)
    else:
        return Response(status=200)

async def github_callback_handler(request):
    event = gh_sansio.Event.from_http(request.headers, await request.read())
    event.app = request.app
    await gh_router.dispatch(event)

async def main(request):
    try:
        body = await request.read()
        secret = os.environ.get("GH_SECRET")
        event = sansio.Event.from_http(request.headers, body, secret=secret)
        print("GH delivery ID", event.delivery_id, file=sys.stderr)
        if event.event == "ping":
            return web.Response(status=200)
        oauth_token = os.environ.get("GH_AUTH")
        async with aiohttp.ClientSession() as session:
            gh = gh_aiohttp.GitHubAPI(
                session,
                os.environ.get("GH_USERNAME"),
                oauth_token=oauth_token,
                cache=cache,
            )
            # Give GitHub some time to reach internal consistency.
            await asyncio.sleep(1)
            await router.dispatch(event, gh)
        try:
            print("GH requests remaining:", gh.rate_limit.remaining)