==== tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSupertype.ts (1 errors) ====
    // subtype checks use the apparent type of the target type
    // S is a subtype of a type T, and T is a supertype of S, if one of the following is true, where S' denotes the apparent type (section 3.8.1) of S:
    
    class Base {
        x: string;
    }
    
    // is String (S) a subtype of U extends String (T)? Would only be true if we used the apparent type of U (T)
    class Derived<U extends String> extends Base { // error
          ~~~~~~~
!!! Class 'Derived<U>' incorrectly extends base class 'Base':
!!!   Types of property 'x' are incompatible:
!!!     Type 'U' is not assignable to type 'string'.
        x: U;
    }