src/vs/workbench/services/hover/browser/hoverWidget.ts/HoverWidget/addFocusTrap
class HoverWidget:	private addFocusTrap() {
		if (!this._enableFocusTraps || this._addedFocusTrap) {
			return;
		}
		this._addedFocusTrap = true;

		// Add a hover tab loop if the hover has at least one element with a valid tabIndex
		const firstContainerFocusElement = this._hover.containerDomNode;
		const lastContainerFocusElement = this.findLastFocusableChild(this._hover.containerDomNode);
		if (lastContainerFocusElement) {
			const beforeContainerFocusElement = dom.prepend(this._hoverContainer, $('div'));
			const afterContainerFocusElement = dom.append(this._hoverContainer, $('div'));
			beforeContainerFocusElement.tabIndex = 0;
			afterContainerFocusElement.tabIndex = 0;
			this._register(dom.addDisposableListener(afterContainerFocusElement, 'focus', (e) => {
				firstContainerFocusElement.focus();
				e.preventDefault();
			}));
			this._register(dom.addDisposableListener(beforeContainerFocusElement, 'focus', (e) => {
				lastContainerFocusElement.focus();
				e.preventDefault();
			}));
		}
	}