| iconName | The name of the icon. |
| tooltip | The tooltip to display when the cursor hovers over the icon. |
| icon | The icon to associate with the GUIContent.image. |
Gets the GUIContent from Unity built-in resources with the given information or creates a GUIContent for a GUI element.
The icon is loaded with a localized tooltip.
Typically, the icon from `Assets/Editor Default Resources/Icons` is fetched using the icon name. Only the name of the icon, without the .png extension is needed.