open class Person(val id: Int, val fullName: String)

class Student(id: Int, fullName: String, val graduationYear: Int) : Person(id, fullName) {
	companion object
}

// In test file:

val Student.Companion.test = Student(id = 1, fullName = "john smith", graduationYear = 2020)

class StudentTest {
    
    lateinit var testSubject: Student
    
    @BeforeAll
    fun setUp() {
        testSubject = Student.test
    }
}