resolveIcon

Option	Explanation
Mithril Object	Here the user can interject and add their own icons, uses m()

Optional Available Parameters	Type	Explanation
this	Object	treebeard object
item	Object	item aced on

Example:

var options = {
    ...
    resolveIcon : function (item) {
                if (item.kind === "folder") {
                    if (item.data.open){
                        return m("i.fa.fa-folder-open-o", " ");
                    }
                    return m("i.fa.fa-folder-o", " ");
                }
                if (item.data.icon) {
                    return m("i.fa." + item.data.icon, " ");
                }
                return m("i.fa.fa-file ");
            },
    ...
}