{ instance: 'Parametric',
  slot1: { instance: 'ConcreteRecord', concreteField: 123 } }
{ instance: 'Parametric',
  slot1: { instance: 'ConcreteRecord', concreteField: 123 } }
{ instance: 'Parametric',
  slot1: { forced: false, value: [Function] } }
{ instance: 'Just',
  slot1: { instance: 'ConcreteRecord', concreteField: 42 } }
{ instance: 'Just',
  slot1: { instance: 'ConcreteRecord', concreteField: 42 } }
{ instance: 'Just',
  slot1: { forced: false, value: [Function] } }
{ forced: false, value: [Function] }
{ instance: 'Just',
  slot1: { forced: false, value: [Function] } }
{ instance: 'Just',
  slot1: { instance: 'ConcreteRecord', concreteField: 42 } }