code: def add_showcase(self, showcase, showcases_to_check=None):
          # type: (Union[hdx.data.showcase.Showcase,Dict,str], List[hdx.data.showcase.Showcase]) -> bool
          
          dataset_showcase = self._get_dataset_showcase_dict(showcase)
          if showcases_to_check is None:
              showcases_to_check = self.get_showcases()
          for showcase in showcases_to_check:
              if dataset_showcase['showcase_id'] == showcase['id']:
                  return False
          showcase = hdx.data.showcase.Showcase({'id': dataset_showcase['showcase_id']}, configuration=self.configuration)
          showcase._write_to_hdx('associate', dataset_showcase, 'package_id')
          return True
docs: Add dataset to showcase
  
          Args:
              showcase (Union[Showcase,Dict,str]): Either a showcase id or showcase metadata from a Showcase object or dictionary
              showcases_to_check (List[Showcase]): list of showcases against which to check existence of showcase. Defaults to showcases containing dataset.
  
          Returns:
              bool: True if the showcase was added, False if already present