docs: def init_index(self, app=None):
          """Create indexes and put mapping."""
          elasticindexes = self._get_indexes()
  
          for index, settings in elasticindexes.items():
              es = settings['resource']
              if not es.indices.exists(index):
                  self.create_index(index, settings.get('index_settings'), es)
                  continue
              else:
                  self.put_settings(app, index, settings.get('index_settings').get('settings'), es)
  
              for mapping_type, mappings in settings.get('index_settings', {}).get('mappings').items():
                  self._put_resource_mapping(mapping_type, es,
                                             properties=mappings,
                                             index=index, doc_type=mapping_type)
          return