question: private static void checkGroups ( String [ ] groups ) { SecurityManager sm = System . getSecurityManager ( ) ; if ( sm == null ) return ; if ( groups != null ) { for ( int i = 0 ; i < groups . length ; i ++ ) { sm . checkPermission ( new DiscoveryPermission ( groups [ i ] ) ) ; } } else { sm . checkPermission ( new DiscoveryPermission ( "*" ) ) ; } }
target:  Determines if the caller has discovery permission for each group.