code: def find_related_module(app, related_name):
      
  
      try:
          app_path = importlib.import_module(app).__path__
      except ImportError as exc:
          warn('Autodiscover: Error importing %s.%s: %r' % (
              app, related_name, exc,
          ))
          return
      except AttributeError:
          return
  
      try:
          f, _, _ = imp.find_module(related_name, app_path)
          # f is returned None when app_path is a module
          f and f.close()
      except ImportError:
          return
  
      return importlib.import_module('{0}.{1}'.format(app, related_name))
docs: Given an application name and a module name, tries to find that
      module in the application.