 {at: 1.5, expect: 'rgb(0, 0, 0) 30px 30px 30px 30px'},
]);

test_interpolation({
  property: 'box-shadow',
  from: 'inherit',
  to: '20px 20px 20px 20px black',
}, [
  {at: -0.3, expect: 'rgb(0, 0, 0) 33px 7px 33px 7px'},
  {at: 0, expect: 'rgb(0, 0, 0) 30px 10px 30px 10px'},
  {at: 0.3, expect: 'rgb(0, 0, 0) 27px 13px 27px 13px'},
  {at: 0.6, expect: 'rgb(0, 0, 0) 24px 16px 24px 16px'},
  {at: 1, expect: 'rgb(0, 0, 0) 20px 20px 20px 20px'},
  {at: 1.5, expect: 'rgb(0, 0, 0) 15px 25px 15px 25px'},
]);

tes