* 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:

      }
    }
    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.

A **Manager** is used to manage all incoming and outgoing connections to a server.

On startup all remote servers must be specified. 
From that individual connections will be spawned to each remote server, 
or incoming requests will be hooked up to the appropriate connection.

To get a connection to a specific server, use `Manager.Connection(host)` to get a connection to the specified host.
From this connection individual requests can be made.

import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.connection.FastFallbackExchangeFinder
import okhttp3.internal.connection.ForceConnectRoutePlanner
import okhttp3.internal.connection.RealConnectionPool
import okhttp3.internal.connection.RealRoutePlanner
import okhttp3.internal.connection.RouteDatabase

/**
 * Manages reuse of HTTP and HTTP/2 connections for reduced network latency. HTTP requests that

import okhttp3.internal.toImmutableList

/**
 * A specification for a connection to an origin server. For simple connections, this is the
 * server's hostname and port. If an explicit proxy is requested (or [no proxy][Proxy.NO_PROXY] is
 * explicitly requested), this also includes that proxy information. For secure connections the
 * address also includes the SSL socket factory, hostname verifier, and certificate pinner.
 *

    }

  /**
   * True if ALPN is used on incoming HTTPS connections to negotiate a protocol like HTTP/1.1 or
   * HTTP/2. This is true by default; set to false to disable negotiation and restrict connections
   * to HTTP/1.1.
   */
  var protocolNegotiationEnabled: Boolean = true

  /**
   * The protocols supported by ALPN on incoming HTTPS connections in order of preference. The list

    return null
  }

  override fun connectionReleased(connection: Connection) {
  }

  override fun connectionConnectionAcquired(connection: RealConnection) {
  }

  override fun connectionConnectionReleased(connection: RealConnection) {
  }

  override fun connectionConnectionClosed(connection: RealConnection) {
  }

  override fun noNewExchanges(connection: RealConnection) {
  }

import okhttp3.internal.ws.RealWebSocket
import okio.BufferedSink
import okio.BufferedSource

/**
 * A connection to a remote web server capable of carrying 1 or more concurrent streams.
 *
 * Connections are shared in a connection pool. Accesses to the connection's state must be guarded
 * by holding a lock on the connection.
 */
class RealConnection(
  val taskRunner: TaskRunner,
  val connectionPool: RealConnectionPool,

  }

  /**
   * Release any resources held by this dispatcher. Any requests that are currently being dispatched
   * should return immediately. Responses returned after shutdown will not be transmitted: their
   * socket connections have already been closed.
   */
  open fun shutdown() {}

_2020-03-08_

 *  Fix: Don't reuse a connection on redirect if certs match but DNS does not. For better
    locality and performance OkHttp attempts to use the same pooled connection across redirects and
    follow-ups. It independently shares connections when the IP addresses and certificates match,
    even if the host names do not. In 4.4.0 we introduced a regression where we shared a connection