message: optional createSnapGrid range
  (shamelessly stolen from
diff: @@ -352,7 +352,7 @@ declare namespace interact {
  stop ( event: any ) : InteractStatic
  pointerMoveTolerance () : number
  pointerMoveTolerance ( tol: number ) : InteractStatic
  - createSnapGrid ( grid: { x: number, y: number, range: number, offset?: Position, limits?: Rect } ) : SnapFunction
  + createSnapGrid ( grid: { x: number, y: number, range?: number, offset?: Position, limits?: Rect } ) : SnapFunction
  isSet ( element: DOMElement | CSSSelector ) : boolean
  addDocument ( document: Document, options: any ) : void
  removeDocument ( document: Document, options: any ) : void
  