if (connectionUser.candidateConnection() != null) {
      check(toClose == null)
      return ReusePlan(candidate)
    }

    // The call's connection was released.
    toClose?.closeQuietly()
    connectionUser.connectionReleased(candidate)
    connectionUser.connectionConnectionReleased(candidate)
    if (toClose != null) {
      connectionUser.connectionConnectionClosed(candidate)

    public boolean close () throws CIFSException {
        boolean inUse = false;

        List<SmbTransportImpl> toClose;
        synchronized ( this.connections ) {
            cleanup();
            log.debug("Closing pool");
            toClose = new LinkedList<>(this.connections);
            toClose.addAll(this.nonPooledConnections);
            this.connections.clear();
            this.nonPooledConnections.clear();

    val connection = this.connection
    if (connection != null) {
      connection.lock.assertNotHeld()
      val toClose: Socket? =
        connection.withLock {
          // Sets this.connection to null.
          releaseConnectionNoEvents()
        }
      if (this.connection == null) {
        toClose?.closeQuietly()
        eventListener.connectionReleased(this, connection)

      val noNewExchangesEvent: Boolean
      val toClose: Socket? =
        connection.withLock {
          noNewExchangesEvent = !connection.noNewExchanges
          connection.noNewExchanges = true
          connectionUser.releaseConnectionNoEvents()
        }
      if (toClose != null) {
        toClose.closeQuietly()
        connectionListener.connectionClosed(connection)

    return optional.isPresent() ? DoubleStream.of(optional.getAsDouble()) : DoubleStream.empty();
  }

  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private static void closeAll(BaseStream<?, ?>[] toClose) {
    // If one of the streams throws an exception, continue closing the others, then throw the
    // exception later. If more than one stream throws an exception, the later ones are added to the

    return optional.isPresent() ? DoubleStream.of(optional.getAsDouble()) : DoubleStream.empty();
  }

  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private static void closeAll(BaseStream<?, ?>[] toClose) {
    // If one of the streams throws an exception, continue closing the others, then throw the
    // exception later. If more than one stream throws an exception, the later ones are added to the