message: last param is optional
diff: public models: IModelMap = {};
  - constructor(font: opentypejs.Font, text: string, fontSize: number, combine = false, centerCharacterOrigin = false, bezierAccuracy: number) {
  + constructor(font: opentypejs.Font, text: string, fontSize: number, combine = false, centerCharacterOrigin = false, bezierAccuracy?: number) {
  var charIndex = 0;
  var combineOptions: ICombineOptions = {};
  