'Test update on `EmbeddedDocumentField` fields.'

def test_embedded_update(self):

    class Page(EmbeddedDocument, ):
        log_message = StringField(verbose_name='Log    message', required=True)
    class Site(Document, ):
        page = EmbeddedDocumentField(Page)
    Site.drop_collection()
    site = Site(page=Page(log_message='Warning:    Dummy    message'))
    site.save()
    site = Site.objects.first()
    site.page.log_message = 'Error:    Dummy    message'
    site.save()
    site = Site.objects.first()
    self.assertEqual(site.page.log_message, 'Error:    Dummy    message')
