Drag'n drop files from explorer on a widget

Hi,

I created a widget in my blueprint and I would like to enable drop events on it to drag files from the explorer.
I saw that there are blocks like “Create Drag Drop Operation”, “Detect Drag if Pressed”, “Get Drag Dropping Content”, … but there is no documentation at all about them.

So how to perform a drop files operation on a widget in a blueprint?

Thanks.