class Expression {

  public static Interpolator cubicBezier(@NonNull Expression x1, @NonNull Expression y1,
                                         @NonNull Expression x2, @NonNull Expression y2) {
    return new Interpolator("cubic-bezier", x1, y1, x2, y2);
  }

    Expression();
  public  Expression(@NonNull String operator, @Nullable Expression... arguments);

}