override val call: Call,
    val connection: Connection,
  ) : CallEvent()

  data class ConnectionReleased(
    override val timestampNs: Long,
    override val call: Call,
    val connection: Connection,
  ) : CallEvent() {
    override fun closes(event: CallEvent): Boolean = event is ConnectionAcquired && call == event.call && connection == event.connection
  }

  data class CallStart(

     * `ID > lastGoodStreamId` on a new connection.  In- flight streams with
     * `ID <= lastGoodStreamId` can only be replayed on a new connection if they are idempotent.
     *
     * @param lastGoodStreamId the last stream ID the peer processed before sending this message. If
     *     [lastGoodStreamId] is zero, the peer processed no frames.
     * @param errorCode reason for closing the connection.

   * That may happen later by the connection pool thread.
   */
  fun cancel()

  /**
   * Carries an exchange. This is usually a connection, but it could also be a connect plan for
   * CONNECT tunnels. Note that CONNECT tunnels are significantly less capable than connections.
   */
  interface Carrier {
    val route: Route

    fun trackFailure(

  internal var isDuplex: Boolean = false
    private set

  /** True if there was an exception on the connection to the peer. */
  internal var hasFailure: Boolean = false
    private set

  internal val connection: RealConnection
    get() = codec.carrier as? RealConnection ?: error("no connection for CONNECT tunnels")

  internal val isCoalescedConnection: Boolean

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.
 *

              orderedNodeConnections.iterator(),
              (NodeConnection<N> connection) -> {
                if (connection instanceof NodeConnection.Succ) {
                  return EndpointPair.ordered(thisNode, connection.node);
                } else {
                  return EndpointPair.ordered(connection.node, thisNode);
                }
              });
    }

		if f != event.NamespaceFormat && f != event.AccessFormat {
			return fmt.Errorf("unrecognized format value")
		}
	}

	if p.ConnectionString != "" {
		// No pq API doesn't help to validate connection string
		// prior connection, so no validation for now.
	} else {
		// Some fields need to be specified when ConnectionString is unspecified
		if p.Port == "" {
			return fmt.Errorf("unspecified port")
		}

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven</groupId>
  <artifactId>p0</artifactId>
  <packaging>pom</packaging>
  <version>1.0</version>

  <scm>
    <connection>scm:svn:http://host/p0</connection>
    <developerConnection>scm:svn:https://host/p0</developerConnection>
    <url>http://host/viewer?path=/p0</url>
  </scm>

  <modules>
    <module>modules/p1</module>
  </modules>

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven</groupId>
  <artifactId>p0</artifactId>
  <packaging>pom</packaging>
  <version>1.0</version>

  <scm>
    <connection>scm:svn:http://host/p0</connection>
    <developerConnection>scm:svn:https://host/p0</developerConnection>
    <url>http://host/viewer?path=/p0</url>
  </scm>

  <modules>
    <module>modules/p1</module>
  </modules>

  fun connectionPreface() {
    this.withLock {
      if (closed) throw IOException("closed")
      if (!client) return // Nothing to write; servers don't send connection headers!
      if (logger.isLoggable(FINE)) {
        logger.fine(format(">> CONNECTION ${CONNECTION_PREFACE.hex()}"))
      }
      sink.write(CONNECTION_PREFACE)
      sink.flush()
    }
  }