src/vs/workbench/contrib/callHierarchy/browser/callHierarchyTree.ts/AccessibilityProvider/getAriaLabel
class AccessibilityProvider:	getAriaLabel(element: Call): string | null {
		if (this.getDirection() === CallHierarchyDirection.CallsFrom) {
			return localize('from', "calls from {0}", element.item.name);
		} else {
			return localize('to', "callers of {0}", element.item.name);
		}
	}