Kotlin Simple Object Field 2
Geoffrey Challen // 2021.9.0
Create a public class called Simple that stores a single private String value.
Simple should implement a public function called setData that accepts a single String and changes the saved
value. (It should not return a value.)
Simple should also implement a public function called getData that returns the saved value.
You should also implement a public constructor allowing the value to be set when the class is created.
You should assert that String passed to the constructor and setValue is not null.