override fun connectionAcquired(
    connection: Connection,
    call: Call,
  ) {
    logEvent(ConnectionEvent.ConnectionAcquired(System.nanoTime(), connection, call))
  }

  override fun connectionReleased(
    connection: Connection,
    call: Call,
  ) {
    if (eventSequence.find { it is ConnectionEvent.ConnectStart && it.connection == connection } != null && connection is RealConnection) {

    }

    @Override public void connectionAcquired(Call call, Connection connection) {
      printEvent("connectionAcquired");
    }

    @Override public void connectionReleased(Call call, Connection connection) {
      printEvent("connectionReleased");
    }

    @Override public void requestHeadersStart(Call call) {
      printEvent("requestHeadersStart");
    }

import okhttp3.CallEvent.CallEnd
import okhttp3.CallEvent.CallStart
import okhttp3.CallEvent.ConnectEnd
import okhttp3.CallEvent.ConnectStart
import okhttp3.CallEvent.ConnectionAcquired
import okhttp3.CallEvent.ConnectionReleased
import okhttp3.CallEvent.DnsEnd
import okhttp3.CallEvent.DnsStart
import okhttp3.CallEvent.FollowUpDecision
import okhttp3.CallEvent.ProxySelectEnd
import okhttp3.CallEvent.ProxySelectStart

      for (delegate in eventListeners) {
        delegate.connectionAcquired(call, connection)
      }
    }

    override fun connectionReleased(
      call: Call,
      connection: Connection,
    ) {
      for (delegate in eventListeners) {
        delegate.connectionReleased(call, connection)
      }
    }

    override fun requestHeadersStart(call: Call) {
      for (delegate in eventListeners) {

   */
  open fun connectionAcquired(
    connection: Connection,
    call: Call,
  ) {}

  /**
   * Invoked when a call no longer uses a connection.
   */
  open fun connectionReleased(
    connection: Connection,
    call: Call,
  ) {}

  /**
   * Invoked when a connection is marked for no new exchanges.
   */
  open fun noNewExchanges(connection: Connection) {}

  ) : ConnectionEvent()

  data class ConnectionAcquired(
    override val timestampNs: Long,
    override val connection: Connection,
    val call: Call,
  ) : ConnectionEvent()

  data class ConnectionReleased(
    override val timestampNs: Long,
    override val connection: Connection,
    val call: Call,
  ) : ConnectionEvent() {
    override fun closes(event: ConnectionEvent): Boolean =

      check(toClose == null)
      return ReusePlan(candidate)
    }

    // The call's connection was released.
    toClose?.closeQuietly()
    call.eventListener.connectionReleased(call, candidate)
    candidate.connectionListener.connectionReleased(candidate, call)
    if (toClose != null) {
      candidate.connectionListener.connectionClosed(candidate)
    } else if (noNewExchangesEvent) {

import okhttp3.CallEvent.CallEnd
import okhttp3.CallEvent.CallStart
import okhttp3.CallEvent.ConnectEnd
import okhttp3.CallEvent.ConnectStart
import okhttp3.CallEvent.ConnectionAcquired
import okhttp3.CallEvent.ConnectionReleased
import okhttp3.CallEvent.DnsEnd
import okhttp3.CallEvent.DnsStart
import okhttp3.CallEvent.FollowUpDecision
import okhttp3.CallEvent.ProxySelectEnd
import okhttp3.CallEvent.ProxySelectStart

response only if the response code is HTTP/1.1 304 Not Modified.
 
 - CallStart
 - **CacheConditionalHit**
 - ConnectionAcquired
 - ... Standard Events...
 - ResponseBodyEnd _(0 bytes)_
 - **CacheHit**
 - ConnectionReleased
 - CallEnd
 
## Cache directory

The cache directory must be exclusively owned by a single instance.

Deleting the cache when it is no longer needed can be done.  However this may delete the purpose of the cache

import okhttp3.CallEvent.CallEnd
import okhttp3.CallEvent.CallStart
import okhttp3.CallEvent.ConnectEnd
import okhttp3.CallEvent.ConnectStart
import okhttp3.CallEvent.ConnectionAcquired
import okhttp3.CallEvent.ConnectionReleased
import okhttp3.CallEvent.DnsEnd
import okhttp3.CallEvent.DnsStart
import okhttp3.CallEvent.FollowUpDecision
import okhttp3.CallEvent.ProxySelectEnd
import okhttp3.CallEvent.ProxySelectStart