SetUserPasswordPlugin set password can run multiple times ?

edit

i read document in http://cloudbase-init.readthedocs.io/en/latest/plugins.html#setting-password-main

i find that Note This plugin can run multiple times (for posting the password if the metadata service supports this).

but That's not what I do in practice. i find the cloudbase-init only one time on boot.
When the host was restarted, only meta-data was requested, the set poasswrod pluging didn't work, and I saw the log as follows: Plugin execution already done, skipping.

Indicates that the password will not be changed at restart

I want to ask, what do you mean by "can run multiple times (for posting the password if the metadata service supports this). " in this document, and how to do that, how to understand.