class Person {
  get fullName() {
    return this.firstName + ' ' + this.lastName;
  }
}

Person.schema = {
  name: 'Person',
  properties: {
    firstName: 'string',
    lastName: 'string',
  },

};

const App: () => React$Node = () => {

  const [realm, setRealm] = useState(null)

  useEffect (()=>{


    Realm.open({
      schema: [
      {
        name: 'Dog', properties: {name: 'string'}
        }, Person
        ]
        }).then(realm => {
          realm.write(() => {
            realm.create('Dog', {name: 'Rex'});

            const john = realm.create('Person', {
              firstName: 'John',
              lastName: 'Smith',
              });
              });

              let dogs = realm.objects('Dog');
              let persons = realm.objects('Person');

              for (let d of dogs)    console.log("dog ", JSON.stringify(d))  
              for (let p of persons) console.log("person ", JSON.stringify(p))              

              setRealm({ realm });
              });
              }, [])