def test_increment_ref(self):
        class SomeField(object):
            def __init__(self, ref):
                self.ref = ref

        display_fields.FieldRegistry.register_field('some_field', SomeField)

        reg = display_fields.FieldRegistry()

        field = reg.create('some_field')
        self.assertEqual(0, field.ref)
        self.assertEqual(SomeField, field.__class__)

        field2 = reg.create('some_field')
        self.assertEqual(1, field2.ref)
        self.assertEqual(SomeField, field2.__class__)
First term is in set of remaining terms.
dataset/ETHPy150Open rbarrois/mpdlcd/tests/test_display_fields.py/FieldRegistryTestCase.test_increment_ref--crossover with--dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/scheduler/filters/json_filter.py/JsonFilter._in