Checks that the struct is a valid as a new instance.
Checks that the struct is a valid as a new instance. If there are any missing required or construction required fields, return a non-empty Seq of Issues.
Method that should be called on every field of a struct to validate new instances of that struct.
Method that should be called on every field of a struct to validate new instances of that struct. This should only called by the generated implementations of validateNewInstance.