code: def _banner_default(self):
          
          # Don't change banner for external kernels
          if self.external_kernel:
              return ''
          show_banner_o = self.additional_options['show_banner']
          if show_banner_o:
              return self.long_banner()
          else:
              return self.short_banner()
docs: Reimplement banner creation to let the user decide if he wants a
          banner or not