: 'polygon(nonzero, 0px 0px, 25px 25px, 50px 50px)',
  to: 'polygon(nonzero, 25px 25px, 50px 50px, 75px 75px)',
}, [
  {at: -0.3, expect: 'polygon(nonzero, -7.5px -7.5px, 17.5px 17.5px, 42.5px 42.5px)'},
  {at: 0, expect: 'polygon(nonzero, 0px 0px, 25px 25px, 50px 50px)'},
  {at: 0.3, expect: 'polygon(nonzero, 7.5px 7.5px, 32.5px 32.5px, 57.5px 57.5px)'},
  {at: 0.6, expect: 'polygon(nonzero, 15px 15px, 40px 40px, 65px 65px)'},
  {at: 1, expect: 'polygon(nonzero, 25px 25px, 50px 50px, 75px 75px)'},
  {at: 1