protected void convertElementToJson(ObjectNode propertiesNode, FlowElement flowElement) {
// will be handled by ServiceTaskJsonConverter
}
protected FlowElement convertJsonToElement(JsonNode elementNode, JsonNode modelNode, Map<String, JsonNode> shapeMap) {
ServiceTask task = new ServiceTask();
task.setType("mail");
addField(PROPERTY_MAILTASK_TO, elementNode, task);
addField(PROPERTY_MAILTASK_FROM, elementNode, task);
addField(PROPERTY_MAILTASK_SUBJECT, elementNode, task);
addField(PROPERTY_MAILTASK_CC, elementNode, task);
addField(PROPERTY_MAILTASK_BCC, elementNode, task);