package http

import (
	"context"
	"net"
	"syscall"
	"time"
)

// CheckPortAvailability - check if given host and port is already in use.
// Note: The check method tries to listen on given port and closes it.
// It is possible to have a disconnected client in this tiny window of time.
func CheckPortAvailability(host, port string, opts TCPOptions) (err error) {
	lc := &net.ListenConfig{

	if err != nil {
		t.Fatal(err)
	}
	req.RequestURI = "/?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=USWUXHGYZQYFYFFIT3RE%2F20170529%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20170529T190139Z&X-Amz-Expires=600&X-Amz-Signature=19b58080999df54b446fc97304eb8dda60d3df1812ae97f3e8783351bfd9781d&X-Amz-SignedHeaders=host&prefix=Hello%2AWorld%2A"

            challenge.scheme,
            url.toUrl(),
            Authenticator.RequestorType.PROXY,
          )
        } else {
          Authenticator.requestPasswordAuthentication(
            url.host,
            proxy.connectToInetAddress(url, dns),
            url.port,
            url.scheme,
            challenge.realm,
            challenge.scheme,
            url.toUrl(),

        client_max_body_size 0;
        # To disable buffering
        proxy_buffering off;
        proxy_request_buffering off;

        location / {
            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

        client_max_body_size 0;
        # To disable buffering
        proxy_buffering off;
        proxy_request_buffering off;

        location / {
            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

		for k, v := range reqHeaders {
			inputBytes += len(k) + len(v)
		}

		// Calculate node name
		nodeName := r.Host
		if globalIsDistErasure {
			nodeName = globalLocalNodeName
		}
		if host, port, err := net.SplitHostPort(nodeName); err == nil {
			if port == "443" || port == "80" {
				nodeName = host
			}
		}

		// Calculate reqPath
		reqPath := r.URL.RawPath
		if reqPath == "" {

		}
		if !enabled {
			continue
		}
		var brokers []xnet.Host
		kafkaBrokers := getCfgVal(EnvKafkaBrokers, k, kv.Get(KafkaBrokers))
		if len(kafkaBrokers) == 0 {
			return cfg, config.Errorf("kafka 'brokers' cannot be empty")
		}
		for _, s := range strings.Split(kafkaBrokers, config.ValueSeparator) {
			var host *xnet.Host
			host, err = xnet.ParseHost(s)
			if err != nil {
				break
			}

            return false;
        }
    }

    private static boolean isLocal(String host) {
        return "localhost".equals(host) || "127.0.0.1".equals(host);
    }

    /**
     * Checks the URL to see if this repository refers to a non-localhost repository using HTTP.
     *
     * @param originalRepository

package okhttp3

import java.net.InetAddress
import java.net.UnknownHostException
import java.util.concurrent.CountDownLatch
import okio.IOException

/**
 * An async domain name service that resolves IP addresses for host names.
 *
 * The main implementations will typically be implemented using specific DNS libraries such as
 *  * Android DnsResolver
 *  * OkHttp DnsOverHttps
 *  * dnsjava Resolver
 *

</div>

то встроенная переменная `__name__`, автоматически создаваемая Python в вашем файле, будет иметь значение строкового типа `"__main__"`.

Тогда выполнится условие и эта часть кода:

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

будет запущена.

---

Но этого не произойдет, если вы импортируете этот модуль (файл).

Таким образом, если у вас есть файл `importer.py` с таким импортом:

```Python