src/vs/workbench/common/views.ts/ViewsRegistry/removeViews
class ViewsRegistry:	private removeViews(viewDescriptors: IViewDescriptor[], viewContainer: ViewContainer): IViewDescriptor[] {
		const views = this._views.get(viewContainer);
		if (!views) {
			return [];
		}
		const viewsToDeregister: IViewDescriptor[] = [];
		const remaningViews: IViewDescriptor[] = [];
		for (const view of views) {
			if (!viewDescriptors.includes(view)) {
				remaningViews.push(view);
			} else {
				viewsToDeregister.push(view);
			}
		}
		if (viewsToDeregister.length) {
			if (remaningViews.length) {
				this._views.set(viewContainer, remaningViews);
			} else {
				this._views.delete(viewContainer);
				this._viewContainers.splice(this._viewContainers.indexOf(viewContainer), 1);
			}
		}
		return viewsToDeregister;
	}