* its parameter type is {@code Object}, not {@code AutoCloseable} or {@code Closeable}.
     *
     * @param closeable the object to be closed (see notes above)
     * @param closingExecutor the object will be closed on this executor
     * @return the first argument
     */
    @CanIgnoreReturnValue
    @ParametricNullness
    public <C extends @Nullable Object & @Nullable AutoCloseable> C eventuallyClose(

     * its parameter type is {@code Object}, not {@code AutoCloseable} or {@code Closeable}.
     *
     * @param closeable the object to be closed (see notes above)
     * @param closingExecutor the object will be closed on this executor
     * @return the first argument
     */
    @CanIgnoreReturnValue
    @ParametricNullness
    public <C extends @Nullable Object & @Nullable AutoCloseable> C eventuallyClose(

        return ensureTreeConnected();
    }

    /**
     * {@inheritDoc}
     * Optimized to provide better resource cleanup with caching benefits.
     *
     * @see java.lang.AutoCloseable#close()
     */
    @Override
    public synchronized void close() {
        final SmbTreeHandleImpl th = this.treeHandle;
        if (th != null) {
            this.treeHandle = null;