code: def alias_package(package, alias, extra_modules={}):
      
      path = package.__path__
      alias_prefix = alias + '.'
      prefix = package.__name__ + '.'
      # Alias all importable modules recursively
      for _, name, _ in pkgutil.walk_packages(path, prefix):
          # Skip databaseds backends
          if name.startswith('tango.databaseds.db_access.'):
              continue
          try:
              if name not in sys.modules:
                  __import__(name)
          except ImportError:
              continue
          alias_name = name.replace(prefix, alias_prefix)
          sys.modules[alias_name] = sys.modules[name]
      # Alias extra modules
      for key, value in extra_modules.items():
          name = prefix + value
          if name not in sys.modules:
              __import__(name)
          if not hasattr(package, key):
              setattr(package, key, sys.modules[name])
          sys.modules[alias_prefix + key] = sys.modules[name]
      # Alias root module
      sys.modules[alias] = sys.modules[package.__name__]
docs: Alias a python package properly.
  
      It ensures that modules are not duplicated by trying
      to import and alias all the submodules recursively.