const cmp = intervalCompare(zAbsoluteStart, zAbsoluteEnd, x.start + delta, x.end + delta);
if (cmp < 0) {
// => it is not affected by the node's delta
if (x.left === SENTINEL) {
z.start -= delta;
z.end -= delta;
z.maxEnd -= delta;
x.left = z;
break;
} else {
x = x.left;
}