private Stanza changeNick(Entity occupantJid, Entity roomWithNickJid) throws ProtocolException {
StanzaBuilder stanzaBuilder = StanzaBuilder.createPresenceStanza(occupantJid, roomWithNickJid, null, null,
null, null);
stanzaBuilder.startInnerElement("x", NamespaceURIs.XEP0045_MUC);
stanzaBuilder.endInnerElement();
Stanza presenceStanza = stanzaBuilder.build();
ResponseStanzaContainer container = handler.execute(presenceStanza, sessionContext.getServerRuntimeContext(),
true, sessionContext, null);
if (container != null) {
return container.getResponseStanza();