Fixed forms import.

import json

from django.core import exceptions, serializers

from django.forms import Form

from . import PostgresSQLTestCase

from .models import HStoreModel

        self.assertIsInstance(form_field, forms.HStoreField)

    def test_empty_field_has_not_changed(self):

        class HStoreFormTest(forms.Form):

        class HStoreFormTest(Form):

            f1 = HStoreField()

        form_w_hstore = HStoreFormTest()

        self.assertFalse(form_w_hstore.has_changed())