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=== tests/cases/conformance/classes/members/inheritanceAndOverriding/derivedClassTransitivity3.ts ===
// subclassing is not transitive when you can remove required parameters and add optional parameters
class C<T> {
>C : C<T>
foo(x: T, y: T) { }
>foo : (x: T, y: T) => void
>x : T
>y : T
}
class D<T> extends C<T> {
>D : D<T>
>C : C<T>
foo(x: T) { } // ok to drop parameters
>foo : (x: T) => void
>x : T
}
class E<T> extends D<T> {
>E : E<T>
>D : D<T>
foo(x: T, y?: number) { } // ok to add optional parameters
>foo : (x: T, y?: number) => void
>x : T
>y : number
}
var c: C<string>;
>c : C<string>
var d: D<string>;
>d : D<string>
var e: E<string>;
>e : E<string>
c = e;
>c = e : E<string>
>c : C<string>
>e : E<string>
var r = c.foo('', '');
>r : void
>c.foo('', '') : void
>c.foo : (x: string, y: string) => void
>c : C<string>
>foo : (x: string, y: string) => void
>'' : ""
>'' : ""
var r2 = e.foo('', 1);
>r2 : void
>e.foo('', 1) : void
>e.foo : (x: string, y?: number) => void
>e : E<string>
>foo : (x: string, y?: number) => void
>'' : ""
>1 : 1
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