human
I wrote the below code

    def test(importer):
        return (importer.__class__.__name__ == ModuleImporterFromVariables.__name__)
    already_registered = any([True for i in sys.meta_path if test(i)])
    if (not already_registered):
        importer = ModuleImporterFromVariables(restrict_to=['SelfWrapper'])
        sys.meta_path.insert(0, importer)
    return (not already_registered)

What's a good function header?
assistant
#Here's a good function header.

def register_importer():