code: def register_importer():
      
  
      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
docs: registers our fancy importer that can let us import from a module name,
      like:
  
          import sh
          tmp = sh()
          from tmp import ls