def build_attrs(self, extra_attrs=None, **kwargs):
        attrs = super(HeavySelect2Mixin, self).build_attrs(extra_attrs=extra_attrs, **kwargs)

        # encrypt instance Id
        self.widget_id = signing.dumps(id(self))

        attrs['data-field_id'] = self.widget_id
        attrs.setdefault('data-ajax--url', self.get_url())
        attrs.setdefault('data-ajax--cache', "true")
        attrs.setdefault('data-ajax--type', "GET")
        attrs.setdefault('data-minimum-input-length', 2)

        attrs['class'] += ' django-select2-heavy'
        return attrs
@see: twisted.names.client.lookupWellKnownServices
dataset/ETHPy150Open applegrew/django-select2/django_select2/forms.py/HeavySelect2Mixin.build_attrs--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/names/common.py/ResolverBase.lookupWellKnownServices