fix(core): update

test/test.ts

@@ -15,6 +15,8 @@ tap.test('should create an instance', async () => {
 tap.test('should create an xml string', async () => {
   const xmlResult = testSmartxml.createXmlFromObject({
     hello: {
+      "@_xlmns:teststring": "hellothere",
+      "@_xlmns:testnumber": 10,
       wow: 'test'
     }
   });

ts/index.ts

@@ -9,7 +9,10 @@ export class SmartXml {
   }
 
   public createXmlFromObject(jsObject: any): string {
-    const jsToXmlParser = new plugins.fastXmlParser.j2xParser({});
+    const jsToXmlParser = new plugins.fastXmlParser.j2xParser({
+      ignoreAttributes: false,
+      attributeNamePrefix: "@_"
+    });
     const xml = jsToXmlParser.parse(jsObject);
     return xml;
   }