let mockedClass = MockStudentManager()
let studentToTest = someStudent //where someStudent is an instance of Student

stub(mockStudentManager) { stub in

  //Two Objects are considered equal here when name, age and CourseName are equal
  when(stub.doesSomethingToStudent(student: equal( to:  student,
                                                   for: EqualityDescriptor(\Student.name),
                                                        EqualityDescriptor(\Student.age),
                                                        EqualityDescriptor(\Student.course.couseName)
                                                 )
                                  )
      ).thenDoNothing()
}