How to flip a polysurface in grasshopper

This maybe a very basic query – how to flip a polysurface in grasshopper? I know there is a button to flip a single surface but how can we flip a polysurface?

You can explode the polysurface, flip the faces with regular flip surface, then join back together.

Or you an use this method from Rhinocommon:

Or Pufferfish has a Flip Polysurface component.

Cool, thanks Michael!