Python-nautilus: add custom emblems (overlap icon)

I am using python-nautilus module and I am trying to add a custom emblem (icon overlay) like:

But I haven't found anything about it.

I can add an existing "media" logo with this code:

import os.path
from gi.repository import Nautilus, GObject

class OnituIconOverlayExtension(GObject.GObject, Nautilus.InfoProvider):
    def __init__(self):
        pass

    def update_file_info(self, file):
        if os.path.splitext(file.get_name())[1] == "fileWithEmblem":
            file.add_emblem("multimedia")

      

        
        
        
      

    

But I would like to add my own icon.

file.add_emblem("my_super_icon.ico")

      

        
        
        
      

    

Do you have an idea? How can i do this?

Thank you in advance!