docs: public static void interpolate(RectF out, RectF start, RectF end, float factor) {
          out.left = interpolate(start.left, end.left, factor);
          out.top = interpolate(start.top, end.top, factor);
          out.right = interpolate(start.right, end.right, factor);
          out.bottom = interpolate(start.bottom, end.bottom, factor);
      }