Add option for TreeView to allow further customization of the `expandIcons` property allowing you to set the field that based on it the expand icon will be displayed.
I've seen that if the items has the property "items" have more than one element, the icon is displaying and when it's empty it does not.
I do have another property to know if an item have sub-items, can it be added a property to change the logic in order to display or not the expand icon?