Does Centera generate the XUID?

We are using the Centera SDK (Centera_SDK-3.3.718) and the tool is passing back an “XUID”.  According to the Centera SDK documentation, the SDK calls the Centera box.  At that time, Centera returns a C-Clip (also named “XSet”).  When the XSet (C-Clip) is created, a XUID is also generated at the same time.  What generates the “XUID”, Centera or the SDK?

Thanks,
Ed