//任务优先级
JsonNode taskPriorityNode = getProperty(PROPERTY_PRIORITY, elementNode);
if(taskPriorityNode != null){
TaskPriority taskPriority = FixFlowFactory.eINSTANCE.createTaskPriority();
Expression taskPriorityExpression = FixFlowFactory.eINSTANCE.createExpression();
taskPriorityExpression.setName(taskPriorityNode.asText());
taskPriorityExpression.setValue(taskPriorityNode.asText());
taskPriority.setExpression(taskPriorityExpression);
BpmnModelUtil.addExtensionElement(task, FixFlowPackage.Literals.DOCUMENT_ROOT__TASK_PRIORITY, taskPriority);
}