@Mock
    SmbPipeHandleImpl handle;

    @Mock
    SmbTreeHandleImpl tree;

    @Mock
    SmbNamedPipe pipe;

    @Mock
    SmbFileHandleImpl fileHandle;

    private SmbPipeOutputStream newStream() throws CIFSException {
        // Arrange common constructor collaborators to avoid touching network/state
        when(handle.getPipe()).thenReturn(pipe);
        when(tree.isSMB2()).thenReturn(true);

        void readNullArrayThrows() throws Exception {
            SmbFileInputStream in = newStream();
            assertThrows(NullPointerException.class, () -> in.read(null));
        }

        @Test
        @DisplayName("readDirect with len <= 0 returns 0")
        void readDirectZeroLen() throws Exception {
            SmbFileInputStream in = newStream();
            byte[] buf = new byte[4];