code: def export_model(self, export_formats, export_dir=None):
          
          export_dir = export_dir or self.logdir
          return self._export_model(export_formats, export_dir)
docs: Exports model based on export_formats.
  
          Subclasses should override _export_model() to actually
          export model to local directory.
  
          Args:
              export_formats (list): List of formats that should be exported.
              export_dir (str): Optional dir to place the exported model.
                  Defaults to self.logdir.
  
          Return:
              A dict that maps ExportFormats to successfully exported models.