snaker-core/src/main/java/org/snaker/engine/parser/impl/DecisionParser.java
protected void parseNode(NodeModel node, Element element) {
		DecisionModel decision = (DecisionModel)node;
		decision.setExpr(element.getAttribute(ATTR_EXPR));
		decision.setHandleClass(element.getAttribute(ATTR_HANDLECLASS));
	}
protected void parseNode(NodeModel node, Element element) {
		DecisionModel decision = (DecisionModel)node;
		decision.setExpr(element.getAttribute(ATTR_EXPR));
		decision.setHandleClass(element.getAttribute(ATTR_HANDLECLASS));
	}
解析decisition节点的特有属性expr