def demo_run(fields, msg, dst=None, src=None):
    print('')
    print(msg)
    if (src is None):
        src = g_src
    if (dst is None):
        dst = {}
    src = valid_container(src)
    dst = valid_container(dst)
    dp = DataPacker(fields)
    try:
        dp.run(src, dst)
    except err.DataPackerError as e:
        print('抛出了异常: ', type(e), e)
    print(json.dumps(dst.raw_data(), indent=4))
    return dst
def demo_run(fields, msg, dst=None, src=None):
    print()
    print(msg)
    if (src is None):
        src = g_src
    if (dst is None):
        dst = {}
    src = valid_container(src)
    dst = valid_container(dst)
    dp = DataPacker(fields)
    try:
        dp.run(src, dst)
    except err.DataPackerError as e:
        print('抛出了异常: ', type(e), e)
    print(json.dumps(dst.raw_data(), indent=4))
    return dst