src/vs/workbench/browser/parts/statusbar/statusbarModel.ts/StatusbarViewModel/doMarkFirstLastVisibleStatusbarItem
class StatusbarViewModel:	private doMarkFirstLastVisibleStatusbarItem(entries: IStatusbarViewModelEntry[]): void {
		let firstVisibleItem: IStatusbarViewModelEntry | undefined;
		let lastVisibleItem: IStatusbarViewModelEntry | undefined;

		for (const entry of entries) {

			// Clear previous first
			entry.container.classList.remove('first-visible-item', 'last-visible-item');

			const isVisible = !this.isHidden(entry.id);
			if (isVisible) {
				if (!firstVisibleItem) {
					firstVisibleItem = entry;
				}

				lastVisibleItem = entry;
			}
		}

		// Mark: first visible item
		if (firstVisibleItem) {
			firstVisibleItem.container.classList.add('first-visible-item');
		}

		// Mark: last visible item
		if (lastVisibleItem) {
			lastVisibleItem.container.classList.add('last-visible-item');
		}
	}