public String toString() {
   StringBuilder builder = new StringBuilder("AxiomSoapMessageFactory[");
   if (soapFactory.getSOAPVersion() == SOAP11Version.getSingleton()) {
     builder.append("SOAP 1.1");
   } else if (soapFactory.getSOAPVersion() == SOAP12Version.getSingleton()) {
     builder.append("SOAP 1.2");
   }
   builder.append(',');
   if (payloadCaching) {
     builder.append("PayloadCaching enabled");
   } else {
     builder.append("PayloadCaching disabled");
   }
   builder.append(']');
   return builder.toString();
 }