=== tests/cases/compiler/extendedInterfaceGenericType.ts ===
interface Alpha<T> {
>Alpha : Symbol(Alpha, Decl(extendedInterfaceGenericType.ts, 0, 0))
>T : Symbol(T, Decl(extendedInterfaceGenericType.ts, 0, 16))

    takesArgOfT(arg: T): Alpha<T>;
>takesArgOfT : Symbol(takesArgOfT, Decl(extendedInterfaceGenericType.ts, 0, 20))
>arg : Symbol(arg, Decl(extendedInterfaceGenericType.ts, 1, 16))
>T : Symbol(T, Decl(extendedInterfaceGenericType.ts, 0, 16))
>Alpha : Symbol(Alpha, Decl(extendedInterfaceGenericType.ts, 0, 0))
>T : Symbol(T, Decl(extendedInterfaceGenericType.ts, 0, 16))

    makeBetaOfNumber(): Beta<number>;
>makeBetaOfNumber : Symbol(makeBetaOfNumber, Decl(extendedInterfaceGenericType.ts, 1, 34))
>Beta : Symbol(Beta, Decl(extendedInterfaceGenericType.ts, 3, 1))
}
interface Beta<T> extends Alpha<T> {
>Beta : Symbol(Beta, Decl(extendedInterfaceGenericType.ts, 3, 1))
>T : Symbol(T, Decl(extendedInterfaceGenericType.ts, 4, 15))
>Alpha : Symbol(Alpha, Decl(extendedInterfaceGenericType.ts, 0, 0))
>T : Symbol(T, Decl(extendedInterfaceGenericType.ts, 4, 15))
}

var alpha: Alpha<number>;
>alpha : Symbol(alpha, Decl(extendedInterfaceGenericType.ts, 7, 3))
>Alpha : Symbol(Alpha, Decl(extendedInterfaceGenericType.ts, 0, 0))

var betaOfNumber = alpha.makeBetaOfNumber();
>betaOfNumber : Symbol(betaOfNumber, Decl(extendedInterfaceGenericType.ts, 8, 3))
>alpha.makeBetaOfNumber : Symbol(Alpha.makeBetaOfNumber, Decl(extendedInterfaceGenericType.ts, 1, 34))
>alpha : Symbol(alpha, Decl(extendedInterfaceGenericType.ts, 7, 3))
>makeBetaOfNumber : Symbol(Alpha.makeBetaOfNumber, Decl(extendedInterfaceGenericType.ts, 1, 34))

betaOfNumber.takesArgOfT(5);
>betaOfNumber.takesArgOfT : Symbol(Alpha.takesArgOfT, Decl(extendedInterfaceGenericType.ts, 0, 20))
>betaOfNumber : Symbol(betaOfNumber, Decl(extendedInterfaceGenericType.ts, 8, 3))
>takesArgOfT : Symbol(Alpha.takesArgOfT, Decl(extendedInterfaceGenericType.ts, 0, 20))