assertThrows(RuntimeException.class, () -> block.decode(buf, 0));
    }

    @Test
    @DisplayName("readAndXWireFormat reads chained plain SMB and marks received")
    void testReadAndXWireFormatWithPlainSMB() {
        DummyPlainSMB next = new DummyPlainSMB();
        // The implementation uses andx.wordCount, which starts at 0 by default
        // We need to test the actual behavior where wordCount is 0