src/vs/workbench/browser/parts/views/viewPaneContainer.ts/ViewPaneContainer/updateViewHeaders
class ViewPaneContainer:	private updateViewHeaders(): void {
		if (this.isViewMergedWithContainer()) {
			this.paneItems[0].pane.setExpanded(true);
			this.paneItems[0].pane.headerVisible = false;
		} else {
			this.paneItems.forEach(i => i.pane.headerVisible = true);
		}
	}