Adds a set of group names to the managed set of groups associated with this registration.
@param groups a String array, none of whose elements may be null,consisting of the group names with which to augment this registration's managed set of groups.
If any element of this parameter duplicates any other element of this parameter, the duplicate will be ignored. If any element of this parameter duplicates any element of the registration's current managed set of groups, the duplicate will be ignored.
If the empty set (equivalent to net.jini.discovery.LookupDiscovery.NO_GROUPS) is input, then this registration's managed set of groups will not change.
If null (equivalent to net.jini.discovery.LookupDiscovery.ALL_GROUPS) is input, this method will throw a NullPointerException.
@throws java.lang.UnsupportedOperationException this exception occurswhen the lookup discovery service has no managed set of groups associated with this registration.
@throws java.lang.NullPointerException this exception occurs wheneither null (net.jini.discovery.LookupDiscovery.ALL_GROUPS) is input to the groups parameter, or one or more of the elements of the groups parameter is null.
@throws java.rmi.RemoteException typically, this exception occurs whenthere is a communication failure between the client and the lookup discovery service. When this exception does occur, this registration's managed set of groups may or may not have been successfully augmented.
@see #removeGroups