declare const fn: <K extends string, V>(object: { [Key in K]: V }) => object;
declare const a: { [index: string]: number };
/*
Argument of type '{ [index: string]: number; }' is not assignable to parameter of type '{ [x: string]: never; }'.
  Index signatures are incompatible.
    Type 'number' is not assignable to type 'never'.
*/
fn(a);