2-8-gen-1.dart

void main() {
  
  final p = SuperPrinter<int>(1);
  p.doPrint();
  
  final pString = SuperPrinter<String>('Awesome dart');
  pString.doPrint();
  
  var st = Student(2020);
  st.name = 'Stas';
  st.surname = 'Konovalov';
  final pStudent = SuperPrinter<Student>(st);
  pStudent.doPrint();
}

class SuperPrinter<T> {
  T myValue;
  SuperPrinter(this.myValue);
  
  void doPrint() {
    print('Try to print $myValue');
  }
}

class User {
  String name;
  String surname;
  int sex; 
}

class Student extends User {
  int yearOfAdmission;
  int get cuttentCourse => (DateTime.now().year - yearOfAdmission + 1);
  
  Student(this.yearOfAdmission);
    
  @override
  String toString() {
    return '$name $surname $yearOfAdmission $cuttentCourse';
  }
}

Зачет. Все ок.