}

  override fun connectionConnectionAcquired(connection: RealConnection) {
  }

  override fun connectionConnectionReleased(connection: RealConnection) {
  }

  override fun connectionConnectionClosed(connection: RealConnection) {
  }

  override fun noNewExchanges(connection: RealConnection) {
  }

  override fun doExtensiveHealthChecks(): Boolean = false

  override fun isCanceled(): Boolean = false

  }

  override fun connectionConnectionReleased(connection: RealConnection) {
    connection.connectionListener.connectionReleased(connection, call)
  }

  override fun connectionConnectionClosed(connection: RealConnection) {
    connection.connectionListener.connectionClosed(connection)
  }

  override fun noNewExchanges(connection: RealConnection) {

  fun connectionReleased(connection: Connection)

  fun connectionConnectionAcquired(connection: RealConnection)

  fun connectionConnectionReleased(connection: RealConnection)

  fun connectionConnectionClosed(connection: RealConnection)

  fun noNewExchanges(connection: RealConnection)

  fun doExtensiveHealthChecks(): Boolean

  fun isCanceled(): Boolean

  fun candidateConnection(): RealConnection?

    toClose?.closeQuietly()
    connectionUser.connectionReleased(candidate)
    connectionUser.connectionConnectionReleased(candidate)
    if (toClose != null) {
      connectionUser.connectionConnectionClosed(candidate)
    } else if (noNewExchangesEvent) {
      connectionUser.noNewExchanges(candidate)
    }
    return null
  }

  /** Plans to make a new connection by deciding which route to try next. */