def _head(self):
        head = self.obj.head()
        if isinstance(self.index, Series):
            if self._is_grouped_by_sliced_column(self.obj, self.index):
                grouped = head.groupby(head[self.index.name])
            else:
                grouped = head.groupby(self.index.head())
        else:
            grouped = head.groupby(self.index)
        grouped = _maybe_slice(grouped, self._slice)
        return grouped
Every Neuron should have a non-blank type
dataset/ETHPy150Open dask/dask/dask/dataframe/groupby.py/_GroupBy._head--crossover with--dataset/ETHPy150Open openworm/PyOpenWorm/tests/DataIntegrityTest.py/DataIntegrityTest.test_neurons_have_types