*/
interface Connection {
  /** Returns the route used by this connection. */
  fun route(): Route

  /**
   * Returns the socket that this connection is using. Returns an
   * [SSL socket][javax.net.ssl.SSLSocket] if this connection is HTTPS. If this is an HTTP/2
   * connection the socket may be shared by multiple concurrent calls.
   */
  fun socket(): Socket

 * When making TLS connections with multiple [connection specs](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-spec/), these are attempted in sequence until the TLS handshake succeeds.

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

When you request a URL with OkHttp, here's what it does:

    connection: Connection,
    route: Route,
    call: Call,
  ) {}

  /**
   * Invoked when a connection is released as no longer required.
   */
  open fun connectionClosed(connection: Connection) {}

  /**
   * Invoked when a call is assigned a particular connection.
   */
  open fun connectionAcquired(
    connection: Connection,
    call: Call,
  ) {}

  /**

 *
 *  4. If there's no existing connection, make a list of routes (which may require blocking DNS
 *     lookups) and attempt a new connection them. When failures occur, retries iterate the list of
 *     available routes.
 *
 * If the pool gains an eligible connection while DNS, TCP, or TLS work is in flight, this finder
 * will prefer pooled connections. Only pooled HTTP/2 connections are used for such de-duplication.
 *

    // which can satisfy a larger policy
    val connection = routePlanner.plans.first().connection
    val http2Connection = connectHttp2(peer, connection, 5)
    setPolicy(pool, address, ConnectionPool.AddressPolicy(5))
    assertThat(pool.connectionCount()).isEqualTo(1)

    // Decrease the connection's max so that another connection is needed

  }

  /**
   * Return the route from [connection] if it should be retried, even if the connection itself is
   * unhealthy. The biggest gotcha here is that we shouldn't reuse routes from coalesced
   * connections.
   */
  private fun retryRoute(connection: RealConnection): Route? {
    return connection.withLock {
      when {
        connection.routeFailureCount != 0 -> null

      }
    }
    return null
  }

  fun put(connection: RealConnection) {
    connection.lock.assertHeld()

    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.

     * automatically send ping frames until either the connection fails or it is closed. This keeps
     * the connection alive and may detect connectivity failures.
     *
     * If the server does not respond to each ping with a pong within `interval`, this client will
     * assume that connectivity has been lost. When this happens on a web socket the connection is

 *  **There is no longer a global singleton connection pool.** In OkHttp 2.x,
    all `OkHttpClient` instances shared a common connection pool by default.
    In OkHttp 3.x, each new `OkHttpClient` gets its own private connection pool.
    Applications should avoid creating many connection pools as doing so
    prevents connection reuse. Each connection pool holds its own set of

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.      

#### Per-Connection Locks