// Then
        verify(mockFileHandle).close();
        verify(mockFile).clearAttributeCache();
        assertFalse(outputStream.isOpen());
    }

    @Test
    void testIsOpen() throws CIFSException {
        // Given
        when(mockTreeHandle.isSMB2()).thenReturn(true);
        when(mockTreeHandle.getSendBufferSize()).thenReturn(65536);
        when(mockFileHandle.isValid()).thenReturn(true);