src/vs/base/common/map.ts/TernarySearchTree/fill
class TernarySearchTree:	fill(values: readonly [K, V][] | V, keys?: readonly K[]): void {
		if (keys) {
			const arr = keys.slice(0);
			shuffle(arr);
			for (let k of arr) {
				this.set(k, (<V>values));
			}
		} else {
			const arr = (<[K, V][]>values).slice(0);
			shuffle(arr);
			for (let entry of arr) {
				this.set(entry[0], entry[1]);
			}
		}
	}