src/vs/base/browser/ui/iconLabel/iconLabel.ts/IconLabel/setupHover
class IconLabel:	private setupHover(htmlElement: HTMLElement, tooltip: string | IIconLabelMarkdownString | undefined): void {
		const previousCustomHover = this.customHovers.get(htmlElement);
		if (previousCustomHover) {
			previousCustomHover.dispose();
			this.customHovers.delete(htmlElement);
		}

		if (!tooltip) {
			htmlElement.removeAttribute('title');
			return;
		}

		if (!this.hoverDelegate) {
			setupNativeHover(htmlElement, tooltip);
		} else {
			const hoverDisposable = setupCustomHover(this.hoverDelegate, htmlElement, tooltip);
			if (hoverDisposable) {
				this.customHovers.set(htmlElement, hoverDisposable);
			}
		}
	}