Conceptually, if a Person is instantiated in code, and then some dogs, and then the dogs are added to the Persons dogs property, when the Person is written to Realm within a write transaction, the dogs will be too! How cool is that?
If there’s in existing person that’s already been written. When it’s read in and new dogs are added to the person (within a write transaction) , they will also also be written.
Lastly, if there are Person and Dogs that have already been written, if a person is read in, and then a dog is read in, when the dog is added the Person Dog property within a write transaction, it will just update the person since the dog already exists.