assertNull(block.andx, "andx should be cleared when batching prevented");
    }

    @Test
    @DisplayName("writeAndXWireFormat chains non-AndX SMB and propagates header fields")
    void testWriteAndXWireFormatChainsPlainSMB() {
        DummyPlainSMB next = new DummyPlainSMB();
        DummyAndXBlock block = new DummyAndXBlock(next);
        block.customBatchLimit = 2; // batchLevel (0) < limit (2) so chaining allowed