src/vs/platform/storage/common/storage.ts/AbstractStorageService/updateKeyTarget
class AbstractStorageService:	private updateKeyTarget(key: string, scope: StorageScope, target: StorageTarget | undefined): void {

		// Add
		const keyTargets = this.getKeyTargets(scope);
		if (typeof target === 'number') {
			if (keyTargets[key] !== target) {
				keyTargets[key] = target;
				this.getStorage(scope)?.set(TARGET_KEY, JSON.stringify(keyTargets));
			}
		}

		// Remove
		else {
			if (typeof keyTargets[key] === 'number') {
				delete keyTargets[key];
				this.getStorage(scope)?.set(TARGET_KEY, JSON.stringify(keyTargets));
			}
		}
	}