// Source open returns a handle that reports size 0
        SmbFileHandleImpl sfd = mock(SmbFileHandleImpl.class);
        when(sfd.getInitialSize()).thenReturn(0L);
        when(src.openUnshared(eq(0), eq(SmbConstants.O_RDONLY), eq(SmbConstants.FILE_SHARE_READ), eq(SmbConstants.ATTR_NORMAL), eq(0)))
                .thenReturn(sfd);

        // openCopyTargetFile should be called by serverSideCopy, so dest.openUnshared must succeed

        this.file = file;
        if (mode.equals("r")) {
            this.openFlags = SmbFile.O_CREAT | SmbFile.O_RDONLY;
        } else if (mode.equals("rw")) {
            this.openFlags = SmbFile.O_CREAT | SmbFile.O_RDWR | SmbFile.O_APPEND;
            write_andx_resp = new SmbComWriteAndXResponse();
            options = WRITE_OPTIONS;

        assertEquals(0x40, SmbConstants.TYPE_COMM);
    }

    @Test
    @DisplayName("Should define open flags constants")
    void testOpenFlagsConstants() {
        assertEquals(0x01, SmbConstants.O_RDONLY);
        assertEquals(0x02, SmbConstants.O_WRONLY);
        assertEquals(0x03, SmbConstants.O_RDWR);
        assertEquals(0x04, SmbConstants.O_APPEND);
        assertEquals(0x0010, SmbConstants.O_CREAT);

        this.unsharedFile = unsharedFile;

        try (SmbTreeHandleInternal th = this.file.ensureTreeConnected()) {
            if (mode.equals("r")) {
                this.openFlags = SmbConstants.O_CREAT | SmbConstants.O_RDONLY;
                this.access = SmbConstants.FILE_READ_DATA;
            } else if (mode.equals("rw")) {
                this.openFlags = SmbConstants.O_CREAT | SmbConstants.O_RDWR | SmbConstants.O_APPEND;