```
import {AbstractControl, Validators} from "@angular/forms";

export class Form extends Validators{
static required(control: AbstractControl){
return super.required(control) ?
  {required: true} :
  undefined
 }
}

```

when I extend Validators get this error

**TS2417: Class static side 'typeof Form' incorrectly extends base class static side 'typeof Validators'.  
The types returned by 'required(...)' are incompatible between these types.  
Type '{ required: boolean; } | undefined' is not assignable to type 'ValidationErrors | null'.  
Type 'undefined' is not assignable to type 'ValidationErrors | null'.**

what can i do