I don't want to declare a struct again. In fact, I can create multiple view objects or business object according to requirements by creating an instance
Set the type of certain fields, which are optional as Option<String> for create_time.
Create a top-level enum, with different variants for different "things"
enum Institute {
Regular(RegularInstitute),
Unregistered(UnregisteredInstitute)
}
Use the former if you have an object which may exist in various "states" - such as initially all institutes are unregisterered, then they get registered.
Use the latter is un-registered institutes and registered institutes both exist and are distinct.
When I print the field, I look at it and return None, but I accept it at the front end. I don't want this field to appear. it can be ignored during serialization