/**
  * Extract payload from the synapse message context.
  *
  * @param messageContext synapse message context
  * @return payload
  */
 public static String collectPayload(MessageContext messageContext) {
   String payload = null;
   try {
     org.apache.axis2.context.MessageContext a2mc =
         ((Axis2MessageContext) messageContext).getAxis2MessageContext();
     if (JsonUtil.hasAJsonPayload(a2mc)) {
       payload = JsonUtil.jsonPayloadToString(a2mc);
     } else {
       payload = messageContext.getEnvelope().toString();
     }
   } catch (Exception e) {
     // SOAP envelop is not created yet
     payload = "NONE";
   }
   return payload;
 }