import java.util.NoSuchElementException;
import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * A set comprising zero or more {@linkplain Range#isEmpty nonempty}, {@linkplain
 * Range#isConnected(Range) disconnected} ranges of type {@code C}.
 *
 * <p>Implementations that choose to support the {@link #add(Range)} operation are required to
 * ignore empty ranges and coalesce connected ranges. For example:
 *
 * <pre>{@code

        return i;
    }

    /*
     * state values
     * 0 - not connected
     * 1 - connecting
     * 2 - run connected
     * 3 - connected
     * 4 - error
     * 5 - disconnecting
     * 6 - disconnected/invalid
     */
    protected volatile int state = 0;

    protected String name = "Transport" + id++;
    private volatile Thread thread;
    private volatile TransportException te;

    protected void finalize () throws Throwable {
        if ( isConnected() && this.usageCount.get() != 0 ) {
            log.warn("Tree was not properly released");
        }
    }


    /**
     * 
     * @return whether the tree is connected
     */
    public boolean isConnected () {
        return this.tid != -1 && this.session.isConnected() && this.connectionState.get() == 2;
    }


    /**

	"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{
		Control: func(network, address string, c syscall.RawConn) error {

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{}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)

        try ( SmbSessionImpl session = getSession() ) {
            if ( isConnected() ) {
                try ( SmbTransportImpl transport = session.getTransport() ) {
                    if ( transport.isDisconnected() || transport.getRemoteHostName() == null ) {
                        /*
                         * Tree/session thinks it is connected but transport disconnected
                         * under it, reset tree to reflect the truth.

     * @return whether the transport has the given capability
     * @throws SmbException
     */
    boolean hasCapability ( int cap ) throws SmbException;


    /**
     * @return whether the transport has been disconnected
     */
    boolean isDisconnected ();


    /**
     * @param hard
     * @param inuse
     * @return whether the connection was in use
     * @throws IOException
     */

## Retrying Requests

Sometimes connections fail: either a pooled connection was stale and disconnected, or the webserver itself couldn’t be reached. OkHttp will retry the request with a different route if one is available.

## [Calls](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-call/)

			return
		}
		if debugPrint {
			fmt.Println(c.Local, "Disconnected. Attempting to reconnect.")
		}
	}
}

func (c *Connection) disconnected() {
	c.outgoing.Range(func(key uint64, client *muxClient) bool {
		if !client.stateless {
			client.cancelFn(ErrDisconnected)
		}
		return true
	})
	if debugReqs {
		fmt.Println(c.String(), "Disconnected. Clearing outgoing.")
	}
	c.outgoing.Clear()

					return
				}
				if c.HealthCheckFn() {
					if atomic.CompareAndSwapInt32(&c.connected, offline, online) {
						now := time.Now()
						disconnected := now.Sub(c.LastConn())
						logger.Event(context.Background(), "healthcheck", "Client '%s' re-connected in %s", c.url.String(), disconnected)
						atomic.StoreInt64(&c.lastConn, now.UnixNano())
					}
					return
				}
				attempt++
				time.Sleep(backOff(attempt))
			}