public static OfflineMessageStore getInstance() {
        return XMPPServer.getInstance().getOfflineMessageStore();
    }
Returns the instance of {@code OfflineMessageStore} being used by the XMPPServer.

@return the instance of {@code OfflineMessageStore} being used by the XMPPServer.
xmppserver/src/main/java/org/jivesoftware/openfire/OfflineMessageStore.java