src/vs/platform/storage/common/storage.ts/AbstractStorageService/emitDidChangeValue
class AbstractStorageService:	protected emitDidChangeValue(scope: StorageScope, key: string): void {

		// Specially handle `TARGET_KEY`
		if (key === TARGET_KEY) {

			// Clear our cached version which is now out of date
			if (scope === StorageScope.GLOBAL) {
				this._globalKeyTargets = undefined;
			} else if (scope === StorageScope.WORKSPACE) {
				this._workspaceKeyTargets = undefined;
			}

			// Emit as `didChangeTarget` event
			this._onDidChangeTarget.fire({ scope });
		}

		// Emit any other key to outside
		else {
			this._onDidChangeValue.fire({ scope, key, target: this.getKeyTargets(scope)[key] });
		}
	}