class Teacher : CollegePerson, Human
{
    var Name:String
    var Gender:String
    var Birthday:Date?
    var yearsExperience: Double

    required init(name: String, birthday: Date?) {
        super.init(SIN: <#T##Int#>, startDate: <#T##Date?#>)
        self.Name=name
        self.Birthday=birthday
    }

    init(varName: String, varBday: Date, varGender: String, VarYears: Double)
    {
        super.init(SIN: <#T##Int#>, startDate: <#T##Date?#>)
        self.Name=varName
        self.Birthday=varBday
        self.Gender=varGender
        self.yearsExperience=VarYears
    }

     func calcAge(birthdate: Date?) -> Int {
        let today = Date()

        let age = Calendar.current.dateComponents([.year], from: birthdate!, to: today)

        return age.year!

    }


}