byte[] out = new byte[256];

        // Act
        int n = handle.sendrecv(out, 1, 10, in, 128);

        // Assert
        assertEquals(42, n);
        ArgumentCaptor<Smb2IoctlRequest> cap = ArgumentCaptor.forClass(Smb2IoctlRequest.class);
        verify(tree).send(cap.capture(), eq(RequestParam.NO_RETRY));
        assertNotNull(cap.getValue()); // captured request should be present
    }

    @Test

        // Intercept the 3-arg write to validate len
        doNothing().when(raf).write(any(byte[].class), anyInt(), anyInt());
        raf.writeBoolean(true);
        raf.writeByte(0x7F);
        ArgumentCaptor<Integer> lenCap = ArgumentCaptor.forClass(Integer.class);
        verify(raf, atLeast(2)).write(any(byte[].class), anyInt(), lenCap.capture());
        assertTrue(lenCap.getAllValues().stream().allMatch(len -> len == 1));
    }