code: function renderSelectionInstantly(element, toSelection) {
    if (element[resetAnimationsOnNextRenderSymbol]) {
      resetAnimations(element);
      element[resetAnimationsOnNextRenderSymbol] = false;
    }
    const animationFractions = mixin.helpers.animationFractionsForSelection(element, toSelection);
    animationFractions.map((animationFraction, index) => {
      const item = element.items[index];
      if (animationFraction != null) {
        showItem(item, true);
        setAnimationFraction(element, index, animationFraction);
      } else {
        showItem(item, false);
      }
    });
  }
docs: /*
  Instantly render (don't animate) the element's items at the given whole or
  fractional selection index.