[Help Wanted] Sub textures in properties

[Disketaa]

Hi! I read the wiki, but I can not achieve same result, sadly.

I have 2 layers in the model

"textures": {
    "layer0": "test",
    "layer1": "test2"
  },

How can I assign the layers to the textures in properties.json?
I tried this:

type=item
items=minecraft:apple
texture.layer0=item/diamond
texture.layer1=item/apple
model=test