function onStartTransform(tweenProp) {
  if (!KEC[tweenProp] && this.valuesEnd[tweenProp]) {
    KEC[tweenProp] = (elem, a, b, v) => {
      // eslint-disable-next-line no-param-reassign
      elem.style[tweenProp] = (a.perspective || b.perspective ? perspective(a.perspective, b.perspective, 'px', v) : '') // one side might be 0
        + (a.translate3d ? translate3d(a.translate3d, b.translate3d, 'px', v) : '') // array [x,y,z]
        + (a.rotate3d ? rotate3d(a.rotate3d, b.rotate3d, 'deg', v) : '') // array [x,y,z]
        + (a.skew ? skew(a.skew, b.skew, 'deg', v) : '') // array [x,y]
        + (a.scale || b.scale ? scale(a.scale, b.scale, v) : ''); // one side might be 0
    };
  }
}
Sets the property update function.
* same to svgTransform, htmlAttributes
@param {string} tweenProp the property name