Returns the filtered/selected GeoQuerySet.

def query(self, force=False):
        """Returns the filtered/selected GeoQuerySet."""
        if not self.is_valid():
            raise forms.ValidationError(self.errors)
        if force:
            self._is_selected = False
        if not self._is_selected:
            if self.queryset is None:
                raise TypeError('Must be QuerySet not %s' %
                                type(self.queryset))
            self.select()
            self._is_selected = True
        return self.queryset