src/vs/workbench/services/views/common/viewContainerModel.ts/ViewContainerModel/setCollapsed
class ViewContainerModel:	setCollapsed(id: string, collapsed: boolean): void {
		const { viewDescriptorItem } = this.find(id);
		if (viewDescriptorItem.state.collapsed !== collapsed) {
			viewDescriptorItem.state.collapsed = collapsed;
		}
		this.viewDescriptorsState.updateState(this.allViewDescriptors);
	}