0px, smooth to 20% 30px)',
      }, [
        {at: -0.3, expect: 'shape(from 2% 2px, smooth to 7% 13px with -3% 86px, smooth to 33% 17px)'},
        {at: 0, expect: 'shape(from 5% 5px, smooth to 10% 10px with 0% 80px, smooth to 30% 20px)'},
        {at: 0.5, expect: 'shape(from 10% 10px, smooth to 15% 5px with 5% 70px, smooth to 25% 25px)'},
        {at: 1.5, expect: 'shape(from 20% 20px, smooth to 25% -5px with 15% 50px, smooth to 15% 35px)'},
      ]);

      test_interpolation({
        property: 'offset