// No port, bad default.
    checkFromStringCase("google.com", -1, "google.com", -1, false);
    checkFromStringCase("192.0.2.1", 65536, "192.0.2.1", -1, false);
    checkFromStringCase("[2001::1]", -1, "2001::1", -1, false);
    checkFromStringCase("2001::3", 65536, "2001::3", -1, false);
  }

  public void testFromStringUnusedDefaultPort() {
    // Default port, but unused.

package http

import (
	"context"
	"net"
	"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{}

			}
			port, err = strconv.Atoi(portStr)
			if err != nil {
				logger.Fatal(fmt.Errorf("invalid arguments passed to --sftp=%s (%v)", arg, err), "unable to start SFTP server")
			}
			if port < 1 || port > 65535 {
				logger.Fatal(fmt.Errorf("invalid arguments passed to --sftp=%s, (port number must be between 1 to 65535)", arg), "unable to start SFTP server")
			}

    // No port, bad default.
    checkFromStringCase("google.com", -1, "google.com", -1, false);
    checkFromStringCase("192.0.2.1", 65536, "192.0.2.1", -1, false);
    checkFromStringCase("[2001::1]", -1, "2001::1", -1, false);
    checkFromStringCase("2001::3", 65536, "2001::3", -1, false);
  }

  public void testFromStringUnusedDefaultPort() {
    // Default port, but unused.

public class SampleServer extends Dispatcher {
  private final SSLContext sslContext;
  private final String root;
  private final int port;

  public SampleServer(SSLContext sslContext, String root, int port) {
    this.sslContext = sslContext;
    this.root = root;
    this.port = port;
  }

  public void run() throws IOException {
    MockWebServer server = new MockWebServer();

        return new Handler(ctx);
    }

    @Test
    @DisplayName("getDefaultPort returns SMB default port")
    void testGetDefaultPort() {
        // Arrange
        Handler handler = newHandler();
        // Act & Assert
        assertEquals(SmbConstants.DEFAULT_PORT, handler.getDefaultPort(), "Default port should match SmbConstants");
    }

    @Test

        path = u.getPath();
        ref = u.getRef();
        if (ref != null) {
            path += '#' + ref;
        }
        port = u.getPort();
        if (port == -1) {
            port = getDefaultPort();
        }
        setURL(u, "smb", u.getHost(), port, u.getAuthority(), u.getUserInfo(), path, u.getQuery(), null);
    }

    /**
     * The default HTTPS port (<code>443</code>).
     */
    public static final int DEFAULT_HTTPS_PORT = 443;

    /**
     * Constructs an HTTPS handler with the specified CIFS context.
     *
     * @param tc context to use
     */
    public Handler(final CIFSContext tc) {
        super(tc);
    }

    /**
     * Returns the default HTTPS port.
     *

 * http://localhost:53203/oauth/}, passing the same port to this class’ constructor.
 */
public final class SlackApi {
  private final HttpUrl baseUrl = HttpUrl.get("https://slack.com/api/");
  private final OkHttpClient httpClient;
  private final Moshi moshi;

  public final String clientId;
  public final String clientSecret;
  public final int port;

  public SlackApi(String clientId, String clientSecret, int port) {

**Only one process** in the server can be listening on a specific **port** in a specific **IP address**. There could be other processes listening on other ports in the same IP address, but only one for each combination of IP address and port.

TLS (HTTPS) uses the specific port `443` by default. So that's the port we would need.

As only one process can be listening on this port, the process that would do it would be the **TLS Termination Proxy**.