empty_form initial value for a modelformset_factory

Question

I try to add initial values to the empty form of a modelformset_factory.

FormSet = modelformset_factory(MyModel, extra=2)
formset = FormSet(queryset=MyModel.objects.none(), initial=[{'foo': 'bar'}, {'foo': 'bar'}])

I would like to set initial value to the formset.empty_form , how can I achieve this ?