### Question:
Failure implements Nonza { @Override public XmlStringBuilder toXML(org.jivesoftware.smack.packet.XmlEnvironment enclosingNamespace) { XmlStringBuilder xml = new XmlStringBuilder(this, enclosingNamespace); xml.rightAngleBracket(); xml.emptyElement(compressFailureError); xml.optElement(stanzaError); xml.closeElement(this); return xml; } Failure(CompressFailureError compressFailureError);  Failure(CompressFailureError compressFailureError, StanzaError stanzaError); @Override String getElementName(); @Override String getNamespace(); CompressFailureError getCompressFailureError(); StanzaError getStanzaError(); @Override XmlStringBuilder toXML(org.jivesoftware.smack.packet.XmlEnvironment enclosingNamespace); static final String ELEMENT; static final String NAMESPACE; static final QName QNAME; }### Answer:
@Test public void withStanzaErrrorFailureTest() throws SAXException, IOException { StanzaError stanzaError = StanzaError.getBuilder() .setCondition(Condition.bad_request) .build(); Failure failure = new Failure(Failure.CompressFailureError.setup_failed, stanzaError); CharSequence xml = failure.toXML(); final String expectedXml = "<failure xmlns='http: + "<setup-failed/>" + "<error xmlns='jabber:client' type='modify'>" + "<bad-request xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>" + "</error>" + "</failure>"; assertXmlSimilar(expectedXml, xml.toString()); }
@Test public void simpleFailureTest() throws SAXException, IOException { Failure failure = new Failure(Failure.CompressFailureError.processing_failed); CharSequence xml = failure.toXML(); final String expectedXml = "<failure xmlns='http: assertXmlSimilar(expectedXml, xml.toString()); }