when(src.openUnshared(anyInt(), anyInt(), anyInt(), anyInt(), anyInt())).thenThrow(new SmbException("boom"));

            SmbTreeHandleImpl sh = newTreeHandle(false); // force non-SMB2 path to avoid server-side branch
            SmbTreeHandleImpl dh = newTreeHandle(false);

            byte[][] buffers = new byte[][] { new byte[8], new byte[8] };

            when(src.toString()).thenReturn("smb://src");