inheritedGenericCallSignature.ts(24,9): error TS2454: Variable 'x' is used before being assigned.
inheritedGenericCallSignature.ts(24,11): error TS2345: Argument of type 'undefined' is not assignable to parameter of type 'Date[]'.


==== inheritedGenericCallSignature.ts (2 errors) ====
    interface I1<T> {
    
        (a: T): T;
    
    }
    
    
    interface Object {}
    
     
    
    interface I2<T> extends I1<T[]> {
    
        b: T;
    
    }
    
     
    
    var x: I2<Date>;
    
     
    
    var y = x(undefined);
            ~
!!! error TS2454: Variable 'x' is used before being assigned.
              ~~~~~~~~~
!!! error TS2345: Argument of type 'undefined' is not assignable to parameter of type 'Date[]'.
    
    y.length;  // should not error
    