=== tests/cases/compiler/assignToPrototype1.ts ===
declare class Point {
>Point : Point

  add(dx: number, dy: number): void;
>add : (dx: number, dy: number) => void
>dx : number
>dy : number
}

Point.prototype.add = function(dx, dy) {
>Point.prototype.add = function(dx, dy) {} : (dx: number, dy: number) => void
>Point.prototype.add : (dx: number, dy: number) => void
>Point.prototype : Point
>Point : typeof Point
>prototype : Point
>add : (dx: number, dy: number) => void
>function(dx, dy) {} : (dx: number, dy: number) => void
>dx : number
>dy : number

};