How to use the nwbwidgets.controllers.GroupAndSortController function in nwbwidgets

def make_group_and_sort(self, window=False):
        discard_rows = np.where(self.trials['stimulus_name'][:] != 'drifting_gratings')[0]
        gas = GroupAndSortController(self.trials, window=window, start_discard_rows=discard_rows)

        return gas

def make_group_and_sort(self, group_by=None):
        return GroupAndSortController(self.units, group_by=group_by)

self.children = [self.stimulus_type_dd] + list(self.children)

    def get_trials(self):
        return self.units.get_ancestor('NWBFile').epochs

    def stimulus_type_dd_callback(self, change):
        self.gas.discard_rows = np.where(self.trials['stimulus_name'][:] != self.stimulus_type_dd.value)[0]

    def make_group_and_sort(self, window=False):
        discard_rows = np.where(self.trials['stimulus_name'][:] != 'drifting_gratings')[0]
        gas = GroupAndSortController(self.trials, window=window, start_discard_rows=discard_rows)

        return gas


class AllenRasterGroupAndSortController(GroupAndSortController):

    def get_groups(self):

        self.electrodes = self.dynamic_table.get_ancestor('NWBFile').electrodes

        groups = super().get_groups()
        groups.update({name: np.unique(self.electrodes[name][:]) for name in self.electrodes.colnames})
        return groups

    def get_orderable_cols(self):
        units_orderable_cols = super().get_orderable_cols()
        candidate_cols = [x for x in self.electrodes.colnames
                          if not (isinstance(self.electrodes[x][0], Iterable) or
                                  isinstance(self.electrodes[x][0], str))]
        return units_orderable_cols + [x for x in candidate_cols
                                       if len(robust_unique(self.electrodes[x][:])) > 1]

def make_group_and_sort(self, window=None):
        return GroupAndSortController(self.trials, window=window)