class A<X> {}

class C<X, Y extends A<X>> {}

var lc = <C>[];
var mc = <C, C>{};

class D<X extends num, Y extends A<X>> {}

var ld = <D>[];
var md = <D, D>{};

class E<X, Y extends X Function()> {}

var le = <E>[];
var me = <E, E>{};

class F<X extends num, Y extends X Function()> {}

var lf = <F>[];
var mf = <F, F>{};
main() {}