DefaultDatasetService errors when handling an ImgLabeling

The error can be reproduced by running the following script (I ran it in the Script Editor):

```python
#@ OpService ops
#@ Img inputData
#@OUTPUT net.imglib2.roi.labeling.ImgLabeling labeling

from net.imglib2.algorithm.labeling.ConnectedComponents import StructuringElement
from net.imglib2.roi.labeling import ImgLabeling;

# otsu threshold and display
thresholded = ops.threshold().otsu(inputData)

# call connected components to label each connected region
labeling = ops.labeling().cca(thresholded, StructuringElement.FOUR_CONNECTED)
```

Start by running the provided script in the Script Editor to capture the DefaultDatasetService error while handling the ImgLabeling result from ops.labeling().cca. Then trace the DefaultDatasetService path involved in that conversion and verify that the reproduced script completes without the reported error.

Written by the indexing model from the issue text.