/**
     * Checks if this transport uses the SMB2 protocol.
     *
     * @return whether this is a SMB2 connection
     * @throws SmbException if an error occurs checking protocol version
     */
    boolean isSMB2() throws SmbException;

    /**
     * Gets the number of currently pending requests.
     *
     * @return number of inflight requests
     */
    int getInflightRequests();

        }
        return r;
    }

    /**
     * @return whether this is SMB2 transport
     * @throws SmbException
     */
    @Override
    public boolean isSMB2() throws SmbException {
        return this.smb2 || getNegotiateResponse() instanceof Smb2NegotiateResponse;
    }

    /**
     * @param digest
     */

    /**
     * @param digest
     *            the digest to set
     * @throws SmbException
     */
    private void setDigest(SMBSigningDigest digest) throws SmbException {
        if (this.transport.isSMB2()) {
            this.digest = digest;
        } else {
            this.transport.setDigest(digest);
        }
    }

    /**
     * @return the digest
     * @throws SmbException
     */

        try {
            if (t != null && isValid()) {
                if (log.isDebugEnabled()) {
                    log.debug("Closing file handle " + this);
                }

                if (t.isSMB2()) {
                    final Smb2CloseRequest req = new Smb2CloseRequest(this.cfg, this.fileId);
                    t.send(req, RequestParam.NO_RETRY);
                } else {

        lenient().when(tree.acquire()).thenReturn(tree);
        lenient().when(tree.getTreeId()).thenReturn(treeId);
        lenient().when(tree.isConnected()).thenReturn(connected);
        lenient().when(tree.isSMB2()).thenReturn(smb2);
    }

    @Test
    @DisplayName("Constructor with null tree throws NPE (byte[] fid variant)")
    void constructor_nullTree_byteArray_throwsNPE() {

        }

        final Smb2NegotiateRequest r = (Smb2NegotiateRequest) req;

        DialectVersion selected = null;
        for (final DialectVersion dv : DialectVersion.values()) {
            if (!dv.isSMB2()) {
                continue;
            }
            if (dv.getDialect() == getDialectRevision()) {
                selected = dv;
            }
        }

        if (selected == null) {

            // Ensure the transport is connected and ready
            transport.ensureConnected();

            // Verify multi-channel capability (SMB3+ required)
            if (!transport.isSMB2() || !transport.hasCapability(0x00000008)) { // SMB2_GLOBAL_CAP_MULTI_CHANNEL
                throw new CIFSException("Server does not support SMB multi-channel capability");
            }

        when(tree.hasCapability(anyInt())).thenAnswer(inv -> ntSmbsCap && inv.getArgument(0).equals(SmbConstants.CAP_NT_SMBS));
        when(tree.areSignaturesActive()).thenReturn(false);
        when(tree.isSMB2()).thenReturn(smb2);

        when(file.openUnshared(anyInt(), anyInt(), anyInt(), anyInt(), anyInt())).thenReturn(fh);
        when(fh.acquire()).thenReturn(fh);
        when(fh.isValid()).thenReturn(true);