==== tests/cases/compiler/instanceSubtypeCheck2.ts (1 errors) ====
    class C1<T> {
        x: C2<T>;
    }
    
    class C2<T> extends C1<T> {
          ~~
!!! instanceSubtypeCheck2.ts(5,7): error TS2141: Class 'C2<T>' cannot extend class 'C1<T>':
!!! 	Types of property 'x' of types 'C2<T>' and 'C1<T>' are incompatible:
!!! 		Type 'String' is missing property 'x' from type 'C2<T>'.
        x: string
    }