Added interface

Backend/tools-services/src/main/java/com/r11/tools/xml/XmlEngine.java

@@ -0,0 +1,12 @@
+package com.r11.tools.xml;
+
+import com.r11.tools.controller.internal.XPathQueryResult;
+
+public interface XmlEngine {
+    XPathQueryResult processXPath(String data, String query, String version);
+    String processXSLT(String data, String transform);
+    String validate(String data, String xsd);
+
+    public String getVersion();
+
+}