How to use DropdownImageField

<%- if @topic_view.topic.tags.present? %>
<%= t 'js.tagging.tags' %>: <%- @topic_view.topic.tags.each do |t| %> <%= t %> <%- end %>
<% end %>

I’m new bie. I use addon GitHub - fullscreeninteractive/silverstripe-dropdownimagefield to create picture selected on dropwdown.
A sample is too short for me :
DropdownImageField::create(‘LanguageID’, ‘Select language’,
LanguageObj::get(), // Source for items.
‘ID’, // Key field on item.
‘Title’, // Caption field on item.
‘Icon’ // Image field on item. Can be a method/relation that returns an image.

So i don’t know how to create LanguageObj::get().
Please help me.