src/vs/platform/contextkey/browser/contextKeyService.ts/AbstractContextKeyService/contextMatchesRules
class AbstractContextKeyService:	public contextMatchesRules(rules: ContextKeyExpression | undefined): boolean {
		if (this._isDisposed) {
			throw new Error(`AbstractContextKeyService has been disposed`);
		}
		const context = this.getContextValuesContainer(this._myContextId);
		const result = (rules ? rules.evaluate(context) : true);
		// console.group(rules.serialize() + ' -> ' + result);
		// rules.keys().forEach(key => { console.log(key, ctx[key]); });
		// console.groupEnd();
		return result;
	}