src/vs/base/common/skipList.ts/SkipList/constructor
class SkipList:	constructor(
		readonly comparator: (a: K, b: K) => number,
		capacity: number = 2 ** 16
	) {
		this._maxLevel = Math.max(1, Math.log2(capacity) | 0);
		this._header = <any>new Node(this._maxLevel, NIL, NIL);
	}