src/vs/base/common/ternarySearchTree.ts/PathIterator/reset
class PathIterator:	reset(key: string): this {
		this._from = 0;
		this._to = 0;
		this._value = key;
		this._valueLen = key.length;
		for (let pos = key.length - 1; pos >= 0; pos--, this._valueLen--) {
			const ch = this._value.charCodeAt(pos);
			if (!(ch === CharCode.Slash || this._splitOnBackslash && ch === CharCode.Backslash)) {
				break;
			}
		}

		return this.next();
	}