src/vs/workbench/browser/parts/activitybar/activitybarPart.ts/ActivitybarPart/placeholderViewContainersValue
class ActivitybarPart:	private get placeholderViewContainersValue(): string {
		if (!this._placeholderViewContainersValue) {
			this._placeholderViewContainersValue = this.getStoredPlaceholderViewContainersValue();
		}

		return this._placeholderViewContainersValue;
	}