==== tests/cases/compiler/inheritance1.ts (12 errors) ====
    class Control {
        private state: any;
    }
    interface SelectableControl extends Control {
        select(): void;
    }
    
    class Button extends Control implements SelectableControl {
        select() { }
    }
    class TextBox extends Control {
        select() { }
    }
    class ImageBase extends Control implements SelectableControl{
          ~~~~~~~~~
!!! Class 'ImageBase' incorrectly implements interface 'SelectableControl':
!!!   Property 'select' is missing in type 'ImageBase'.
    }
    class Image1 extends Control {
    }
    class Locations implements SelectableControl {
          ~~~~~~~~~
!!! Class 'Locations' incorrectly implements interface 'SelectableControl':
!!!   Property 'state' is missing in type 'Locations'.
        select() { }
    }
    class Locations1 {
        select() { }
    }
    var sc: SelectableControl;
    var c: Control;
    
    var b: Button;
    sc = b;
    c = b;
    b = sc;
    b = c;
    ~
!!! Type 'Control' is not assignable to type 'Button':
!!!   Property 'select' is missing in type 'Control'.
    
    var t: TextBox;
    sc = t;
    c = t;
    t = sc;
    t = c;
    ~
!!! Type 'Control' is not assignable to type 'TextBox':
!!!   Property 'select' is missing in type 'Control'.
    
    var i: ImageBase;
    sc = i;
    ~~
!!! Type 'ImageBase' is not assignable to type 'SelectableControl'.
    c = i;
    i = sc;
    i = c;
    
    var i1: Image1;
    sc = i1;
    ~~
!!! Type 'Image1' is not assignable to type 'SelectableControl':
!!!   Property 'select' is missing in type 'Image1'.
    c = i1;
    i1 = sc;
    i1 = c;
    
    var l: Locations;
    sc = l;
    ~~
!!! Type 'Locations' is not assignable to type 'SelectableControl'.
    c = l;
    ~
!!! Type 'Locations' is not assignable to type 'Control':
!!!   Property 'state' is missing in type 'Locations'.
    l = sc;
    l = c;
    ~
!!! Type 'Control' is not assignable to type 'Locations':
!!!   Property 'select' is missing in type 'Control'.
    
    var l1: Locations1;
    sc = l1;
    ~~
!!! Type 'Locations1' is not assignable to type 'SelectableControl':
!!!   Property 'state' is missing in type 'Locations1'.
    c = l1;
    ~
!!! Type 'Locations1' is not assignable to type 'Control':
!!!   Property 'state' is missing in type 'Locations1'.
    l1 = sc;
    l1 = c;
    ~~
!!! Type 'Control' is not assignable to type 'Locations1':
!!!   Property 'select' is missing in type 'Control'.