function boxModelOnStart(tweenProp) {
  if (tweenProp in this.valuesEnd && !KEC[tweenProp]) {
    KEC[tweenProp] = (elem, a, b, v) => {
      /* eslint-disable no-param-reassign -- impossible to satisfy */
      /* eslint-disable no-bitwise -- impossible to satisfy */
      elem.style[tweenProp] = `${v > 0.99 || v < 0.01
        ? ((numbers(a, b, v) * 10) >> 0) / 10
        : (numbers(a, b, v)) >> 0}px`;
      /* eslint-enable no-bitwise */
      /* eslint-enable no-param-reassign */
    };
  }
}
Sets the update function for the property.
@param {string} tweenProp the property name