diff --git a/build.gradle b/build.gradle
index bf81db1..e3752b5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -40,7 +40,6 @@ repositories {
 dependencies {
     api 'com.google.code.gson:gson:2.8.8'
     api 'log4j:log4j:1.2.17'
-  //  api 'net.dona.doip:doip-sdk:2.1.0'
     api 'org.apache.logging.log4j:log4j-core:2.17.0'
     api 'org.apache.logging.log4j:log4j-api:2.17.0'
     testImplementation 'junit:junit:4.13.2'
diff --git a/src/main/java/org/bdware/mockjava/JsonUtil.java b/src/main/java/org/bdware/mockjava/JsonUtil.java
deleted file mode 100644
index 4f4edcb..0000000
--- a/src/main/java/org/bdware/mockjava/JsonUtil.java
+++ /dev/null
@@ -1,65 +0,0 @@
-package org.bdware.mockjava;
-
-import com.google.gson.*;
-import jdk.nashorn.api.scripting.ScriptObjectMirror;
-
-import java.util.HashSet;
-import java.util.Set;
-
-public class JsonUtil {
-    private static Set<Object> recorded = null;
-
-    public static JsonElement toJson(jdk.nashorn.api.scripting.ScriptObjectMirror res) {
-        recorded = new HashSet<>();
-        JsonElement jsonElement = copyInternal(res);
-        recorded.clear();
-        return jsonElement;
-    }
-
-    private static JsonElement copyInternal(Object obj) {
-        if (recorded.contains(obj)) return JsonNull.INSTANCE;
-        if (obj == null) return JsonNull.INSTANCE;
-        if (obj.getClass() == jdk.nashorn.internal.runtime.Undefined.class)
-            return JsonNull.INSTANCE;
-        if (obj.getClass() == ScriptObjectMirror.class) {
-            recorded.add(obj);
-            ScriptObjectMirror som = (ScriptObjectMirror) obj;
-            if (som.isFunction()) {
-                return JsonNull.INSTANCE;
-            }
-            if (som.isArray()) {
-                JsonArray jarray = new JsonArray();
-
-                for (String str : som.getOwnKeys(true)) {
-                    try {
-                        if (Integer.parseInt(str) >= 0)
-                            jarray.add(copyInternal(som.getMember(str)));
-                    } catch (Exception e) {
-                        // System.out.println("[JSONTool] ignore key:"+str);
-                    }
-                }
-                return jarray;
-            } else {
-                JsonObject jo = new JsonObject();
-                for (String str : som.getOwnKeys(true)) {
-                    jo.add(str, copyInternal(som.getMember(str)));
-                }
-                return jo;
-            }
-        } else if (obj.getClass() == jdk.internal.dynalink.beans.StaticClass.class) {
-            return JsonNull.INSTANCE;
-        } else if (obj instanceof Number) {
-            return new JsonPrimitive((Number) obj);
-
-        } else if (obj instanceof String) {
-            return new JsonPrimitive((String) obj);
-
-        } else if (obj instanceof Character) {
-            return new JsonPrimitive((Character) obj);
-        }
-        if (obj instanceof Boolean) {
-            return new JsonPrimitive((Boolean) obj);
-        }
-        return JsonNull.INSTANCE;
-    }
-}
\ No newline at end of file