Question about "python examples/cmd/run.py" command

[ssxlulu]

I see the run.py code, which show the usage about the run.py script. And I see the argument about --spk which could assignment the speaker.
However, I don't know how to use the --spk argument to assignment the speaker, and there is no examples about it.
Could anyone know it.
Here is my usage, and it doesn't work.

python examples/cmd/run.py --spk 7777 "Hello"