def reset_stm_test_result(test_result):
""" reset root result data and delete all children
STmTestResult is root result object.
"""
logger.debug('Reset StmTestResult object')
iteration_result = test_result.GetObject('StmIteratorResult')
if iteration_result is not None:
iteration_result.MarkDelete()
test_result.Set(Info.get_stc_property_name(), "")
test_result.Set(Status.get_stc_property_name(), "")
test_result.SetCollection(get_stc_json_collection_name(), [])
