case class Person(name: String, age: Int)
val person1 = Person("Robert", 45)
val person2 = Person("Jennifer", 38)
val person3 = Person("Sharon", 51)
val person4 = Person("Robert", 45)
val peopleSet: Set[Person] = Set(person1, person2, person3, person4)
println(peopleSet)
/*
run:
Set(Person(Robert,45), Person(Jennifer,38), Person(Sharon,51))
*/