@Override
    public String getCode() {
        return "http://jabber.org/protocol/event#group-member-added";
    }
Notifies the that a member was added to the group. It can be used by user providers to notify Openfire of the
addition of a member to a group.

@author Gabriel Guarincerri
xmppserver/src/main/java/org/jivesoftware/openfire/commands/event/GroupMemberAdded.java