public String getGUID() returns the GUID of the
      site.
    Parameters
None
Returns
Returns a string representing the globally unique identifier (GUID) of the site.
Example
    SiteService ss = session.getServiceRegistry()
    		.getSiteService();		
    
    Site site = ss.getSite("testsite");
    
    Log.d(TAG, "getGUID: " + site.getGUID());
    
      Would result in output such as the following:
    getGUID: workspace://SpacesStore//431fcaed-c36e-4a52-8e0c-cbd3f75959a8
        
      
      Note that on-premise SkyVault will return the NodeRef as the GUID. On SkyVault Cloud a unique ID, based on the NodeRef, will be returned.
Note: This method was added in version 1.1.