t, end, duration, easing, callback) {
    const anim = document.createElement("m-attr-anim");
    anim.setAttribute("attr", attr);
    anim.setAttribute("start", start);
    anim.setAttribute("end", end);
    anim.setAttribute("start-time", document.timeline.currentTime);
    anim.setAttribute("end-time", document.timeline.currentTime + duration);
    anim.setAttribute("duration", duration);
    anim.setAttribute("easing", easing);
    anim.setAttribute("loop", false);
    element.appendChild(anim);
    set