增加一点测试代码

weixin-java-pay/src/test/java/com/github/binarywang/wxpay/bean/notify/WxPayNotifyResponseTest.java

@@ -0,0 +1,23 @@
+package com.github.binarywang.wxpay.bean.notify;
+
+import org.testng.annotations.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * WxPayNotifyResponse 测试.
+ *
+ * @author <a href="https://github.com/binarywang">Binary Wang</a>
+ * @date 2019-06-30
+ */
+public class WxPayNotifyResponseTest {
+
+  @Test
+  public void testSuccess() {
+    final String result = WxPayNotifyResponse.success("OK");
+    assertThat(result).isEqualTo("<xml>\n" +
+      "  <return_code><![CDATA[SUCCESS]]></return_code>\n" +
+      "  <return_msg><![CDATA[OK]]></return_msg>\n" +
+      "</xml>");
+  }
+}