code: def validate(export_formats):
          
          for i in range(len(export_formats)):
              export_formats[i] = export_formats[i].strip().lower()
              if export_formats[i] not in [
                      ExportFormat.CHECKPOINT, ExportFormat.MODEL
              ]:
                  raise TuneError("Unsupported export format: " +
                                  export_formats[i])
docs: Validates export_formats.
  
          Raises:
              ValueError if the format is unknown.