def get_form(self, request, obj=None, **kwargs):
    base = super(UndeletePageAdminMixin, self).get_form(request, obj, **kwargs)
    base_field = base.base_fields['root_node']
    return type(base.__class__)(base.__class__.__name__, (base,), {'root_node': UndeleteField(site=base_field.site, queryset=base_field.queryset, empty_label=None, label=_('root node'))})
def get_form(self, request, obj=None, **kwargs):
    base = super(UndeletePageAdminMixin, self).get_form(request, obj, **kwargs)
    base_field = base.base_fields['root_node']
    return type(base.__class__)(base.__class__.__name__, (base,), {'root_node': UndeleteField(site=base_field.site, queryset=base_field.queryset, empty_label=None, label=_('root node'))})