takeFromEndWhile(predicate) {
        // P(k) := this.firstIdx >= k && predicate(this.items[k])
        // Find s := max { k | k <= this.lastIdx && !P(k) } and return this.data(s...this.lastIdx]
        let endIdx = this.lastIdx;
        while (endIdx >= 0 && predicate(this.items[endIdx])) {
            endIdx--;
        }
        const result = endIdx === this.lastIdx ? null : this.items.slice(endIdx + 1, this.lastIdx + 1);
        this.lastIdx = endIdx;
        return result;
    }
Consumes elements from the end of the queue as long as the predicate returns true.
If no elements were consumed, `null` is returned.
The result has the same order as the underlying array!