Import a global template render layer with python

[jEchoes]

Hello, I'm struggling to find any info on how to import a template layer with  python.

I have found this

def importRenderSetup(filename):
    with open(filename, "r") as file:
        renderSetup.instance().decode(json.load(file), renderSetup.DECODE_AND_OVERWRITE, None)

But I guess this is erroring out because its for a setup, not a layer. 

Any leads appreciated.

Thanks!