'If a widget has no id, label_tag just returns the text with no
surrounding <label>.'

def test_boundfield_label_tag_no_id(self):

    class SomeForm(Form, ):
        field = CharField()
    boundfield = SomeForm(auto_id='')['field']
    self.assertHTMLEqual(boundfield.label_tag(), 'Field:')
    self.assertHTMLEqual(boundfield.label_tag('Custom&'), 'Custom&amp;:')
