How to load map state ( after save it )

[Hei Jo]

I saw at the PHPMapScript Class Reference show that it can be save a map
state by using this menthod: 
int save(string filename)
Save current map object state to a file. Returns -1 on error.
Use absolute path. If a relative path is used, then it will be
relative to the mapfile location.

But how can we do to load that state ?!
Thanks!