src/vs/platform/contextkey/browser/contextKeyService.ts/Context/setValue
class Context:	public setValue(key: string, value: any): boolean {
		// console.log('SET ' + key + ' = ' + value + ' ON ' + this._id);
		if (this._value[key] !== value) {
			this._value[key] = value;
			return true;
		}
		return false;
	}