def segmentLabelsForKey(self, key):
        return self._mapKeysToLabels[key]
given a key (a directory name in self.outputPath), return all
dataset/ETHPy150Open ilastik/ilastik-0.5/ilastik/modules/interactive_segmentation/core/interactiveSegmentationModuleMgr.py/InteractiveSegmentationItemModuleMgr.segmentLabelsForKey