def choices(self, changelist):
    (yield {'selected': (self.value() is None), 'query_string': changelist.get_query_string(remove=[self.parameter_name]), 'display': 'All', 'initial': True})
    for (lookup, title) in self.lookup_choices:
        (yield {'selected': (str(lookup) in self.value_as_list()), 'query_string': changelist.get_query_string({self.parameter_name: lookup}), 'include_query_string': self._update_query(changelist, include=str(lookup)), 'exclude_query_string': self._update_query(changelist, exclude=str(lookup)), 'display': title})
def choices(self, changelist):
    (yield {'selected': (self.value() is None), 'query_string': changelist.get_query_string(remove=[self.parameter_name]), 'display': 'All', 'initial': True})
    for (lookup, title) in self.lookup_choices:
        (yield {'selected': (str(lookup) in self.value_as_list()), 'query_string': changelist.get_query_string({self.parameter_name: lookup}), 'include_query_string': self._update_query(changelist, include=str(lookup)), 'exclude_query_string': self._update_query(changelist, exclude=str(lookup)), 'display': title})