Converts original result via given converter..

def GetExportedResult(self,
                        original_result,
                        converter,
                        metadata=None,
                        token=None):
    """Converts original result via given converter.."""

    exported_results = list(
        converter.Convert(
            metadata or ExportedMetadata(), original_result, token=token))

    if not exported_results:
      raise ExportError("Got 0 exported result when a single one "
                        "was expected.")

    if len(exported_results) > 1:
      raise ExportError("Got > 1 exported results when a single "
                        "one was expected, seems like a logical bug.")

    return exported_results[0]