// When & Then
        assertTrue(outputStream.isOpen());

        when(mockFileHandle.isValid()).thenReturn(false);
        assertFalse(outputStream.isOpen());
    }

    @Test
    void testWriteAfterClose() throws IOException, CIFSException {
        // Given
        when(mockTreeHandle.isSMB2()).thenReturn(true);
        when(mockTreeHandle.getSendBufferSize()).thenReturn(65536);