address may also share the same underlying TCP socket connection. Sharing a connection has substantial performance benefits: lower latency, higher throughput (due to [TCP slow start](https://www.igvita.com/2011/10/20/faster-web-vs-tcp-slow-start/)) and conserved battery. OkHttp uses a [ConnectionPool](https://square.github.io/okhttp/5.x/okhttp/okhttp3/-connection-pool/) that automatically reuses HTTP/1.x connections and multiplexes HTTP/2 connections.

In OkHttp some fields of the address come...

 * idleConnectionTimeout the timeout duration (in milliseconds) for idle connections
 *
 * <p>Methods:</p>
 * <ul>
 *   <li>{@link #expired()}: Handles the expiration of connections by closing expired and idle connections.</li>
 * </ul>
 *
 * <p>Logging:</p>
 * <ul>
 *   <li>Logs a warning if the clientConnectionManager is null.</li>
 *   <li>Logs a warning if an exception occurs during connection monitoring.</li>

      }
    }
    return null
  }

  fun put(connection: RealConnection) {
    connection.assertLockHeld()

    connections.add(connection)
//    connection.queueEvent { connectionListener.connectEnd(connection) }
    scheduleCloser()
  }

  /**
   * Notify this pool that [connection] has become idle. Returns true if the connection has been
   * removed from the pool and should be closed.

 * idleConnectionTimeout the timeout duration (in milliseconds) for idle connections
 *
 * <p>Methods:</p>
 * <ul>
 *   <li>{@link #expired()}: Handles the expiration of connections by closing expired and idle connections.</li>
 * </ul>
 *
 * <p>Logging:</p>
 * <ul>
 *   <li>Logs a warning if the clientConnectionManager is null.</li>
 *   <li>Logs a warning if an exception occurs during connection monitoring.</li>

    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    return (connectionsU != null) && connectionsU.successors().contains(nodeV);
  }

  private final @Nullable V edgeValueOrDefaultInternal(N nodeU, N nodeV, @Nullable V defaultValue) {
    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    V value = (connectionsU == null) ? null : connectionsU.value(nodeV);

import okhttp3.internal.indexOf
import okhttp3.internal.intersect

/**
 * Specifies configuration for the socket connection that HTTP traffic travels through. For `https:`
 * URLs, this includes the TLS version and cipher suites to use when negotiating a secure
 * connection.
 *
 * The TLS versions configured in a connection spec are only be used if they are also enabled in the

 *   <li>DEFAULT_MAX_CONNECTION_PER_ROUTE_PROPERTY: Default maximum connections per route.</li>
 *   <li>MAX_TOTAL_CONNECTION_PROPERTY: Maximum total connections.</li>
 *   <li>TIME_TO_LIVE_TIME_UNIT_PROPERTY: Time to live unit for connections.</li>
 *   <li>TIME_TO_LIVE_PROPERTY: Time to live for connections.</li>
 * </ul>
 *
 * @author shinsuke
 */

     *
     * * **Stale pooled connections.** The [ConnectionPool] reuses sockets
     *   to decrease request latency, but these connections will occasionally time out.
     *
     * * **Unreachable proxy servers.** A [ProxySelector] can be used to
     *   attempt multiple proxy servers in sequence, eventually falling back to a direct
     *   connection.
     *

closed, up to a conservative limit, to allow better connection reuse. For most
programs, this change should be a no-op, or result in a performance improvement.
In rare cases, programs that do not benefit from connection reuse might
experience performance degradation if they had been improperly allowing an
excessive amount of idle connections to linger; usually by setting

## 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/5.x/okhttp/okhttp3/-call/)