code: def get_cli(cls) -> click.Group:
          
          main = super().get_cli()
  
          if cls.is_namespace:
              @main.group()
              def belns():
                  """Manage BEL namespace."""
  
              cls._cli_add_to_bel_namespace(belns)
              cls._cli_add_clear_bel_namespace(belns)
              cls._cli_add_write_bel_namespace(belns)
  
          if cls.is_annotation:
              @main.group()
              def belanno():
                  """Manage BEL annotation."""
  
              cls._cli_add_write_bel_annotation(belanno)
  
          return main
docs: Get a :mod:`click` main function with added BEL namespace commands.