[PyMOL] how to show PBC box?

Hello:

I am visualizing a MD simulation system in PyMOL. It contains the PBC 
information. I am just wondering how can we show the PBC box in PyMOL? 
As far as I know the PBC box can be shown in VMD using the following 
command line:

 >pbc box

Is there any similar command line in PyMOL?

Thank you very much.

Albert