public void addAdminAccount(String username) {
        if (adminList == null) {
            loadAdminList();
        }
        JID userJID = XMPPServer.getInstance().createJID(username, null);
        if (adminList.contains(userJID)) {
            // Already have them.
            return;
        }
        // Add new admin to cache.
        adminList.add(userJID);
        // Store updated list of admins with provider.
        provider.setAdmins(adminList);
    }
Adds a new account to the list of Admin accounts, based off a username, which will be converted
into a JID.

@param username Username of account to add to list of admins.
xmppserver/src/main/java/org/jivesoftware/openfire/admin/AdminManager.java