==== tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithObjectMembers5.ts (3 errors) ====
    interface Base {
        foo: string;
    }
    
    interface Derived extends Base {
        bar: string;
    }
    
    // N and M have the same name, same accessibility, same optionality, and N is a subtype of M
    // foo properties are valid, bar properties cause errors in the derived class declarations
    module NotOptional {
        interface A {
            foo: Base;
        }
    
        class B implements A {
              ~
!!! Class 'B' incorrectly implements interface 'A':
!!!   Property 'foo' is missing in type 'B'.
            fooo: Derived; // error
        }
    
        interface A2 {
            1: Base;
        }
    
        class B2 implements A2 {
              ~~
!!! Class 'B2' incorrectly implements interface 'A2':
!!!   Property '1' is missing in type 'B2'.
            2: Derived; // error
        }
    
        interface A3 {
            '1': Base;
        }
    
        class B3 implements A3 {
              ~~
!!! Class 'B3' incorrectly implements interface 'A3':
!!!   Property ''1'' is missing in type 'B3'.
            '1.0': Derived; // error
        }
    }
    
    // same cases as above but with optional
    module Optional {
        interface A {
            foo?: Base;
        }
    
        class B implements A {
            fooo: Derived; // ok
        }
    
        interface A2 {
            1?: Base;
        }
    
        class B2 implements A2 {
            2: Derived; // ok
        }
    
        interface A3 {
            '1'?: Base;
        }
    
        class B3 implements A3 {
            '1.0': Derived; // ok
        }
    }