code: def vim_janus(uninstall=None):
      '''Install or update Janus, a distribution of addons and mappings for vim.
  
      More info:
        https://github.com/carlhuda/janus
        Customization: https://github.com/carlhuda/janus/wiki/Customization
  
      Args:
          uninstall: If not None, Uninstall janus and restore old vim config
      '''
      if uninstall is not None:
          uninstall_janus()
      else:
          if not exists('~/.vim/janus'):
              print_msg('not installed => install')
              install_janus()
          else:
              print_msg('already installed => update')
              update_janus()
          customize_janus()
          show_files_used_by_vim_and_janus(f vim_janus(uninstall=None):
      '''Install or update Janus, a distribution of addons and mappings for vim.
  
      More info:
        https://github.com/carlhuda/janus
        Customization: https://github.com/carlhuda/janus/wiki/Customization
  
      Args:
          uninstall: If not None, Uninstall janus and restore old vim config
      '''
      if uninstall is not None:
          uninstall_janus()
      else:
          if not exists('~/.vim/janus'):
              print_msg('not installed => install')
              install_janus()
          else:
              print_msg('already installed => update')
              update_janus()
          customize_janus()
          show_files_used_by_vim_and_janus()
docs: Install or update Janus, a distribution of addons and mappings for vim.
  
      More info:
        https://github.com/carlhuda/janus
        Customization: https://github.com/carlhuda/janus/wiki/Customization
  
      Args:
          uninstall: If not None, Uninstall janus and restore old vim config