def _results_cache_field(cls):
        """The :class:`fiftyone.core.dataset.Dataset` field that stores the
        results cache for these runs.
        """
        raise NotImplementedError(
            "subclass must implement _results_cache_field()"
        )
The :class:`fiftyone.core.dataset.Dataset` field that stores the
        results cache for these runs.
        
fiftyone/core/runs.py