src/vs/workbench/browser/parts/editor/noTabsTitleControl.ts/NoTabsTitleControl/onTitleAuxClick
class NoTabsTitleControl:	private onTitleAuxClick(e: MouseEvent): void {
		if (e.button === 1 /* Middle Button */ && this.group.activeEditor) {
			EventHelper.stop(e, true /* for https://github.com/microsoft/vscode/issues/56715 */);

			this.group.closeEditor(this.group.activeEditor);
		}
	}