diff --git a/src/main/java/com/alibaba/testable/generator/TestableClassDevRoleGenerator.java b/src/main/java/com/alibaba/testable/generator/TestableClassDevRoleGenerator.java
index 26bc54a..ad82e57 100644
--- a/src/main/java/com/alibaba/testable/generator/TestableClassDevRoleGenerator.java
+++ b/src/main/java/com/alibaba/testable/generator/TestableClassDevRoleGenerator.java
@@ -5,7 +5,6 @@ import com.alibaba.testable.generator.statement.CallSuperMethodStatementGenerato
 import com.alibaba.testable.model.TestableContext;
 import com.alibaba.testable.translator.TestableClassDevRoleTranslator;
 import com.alibaba.testable.util.ConstPool;
-import com.alibaba.testable.util.StringUtil;
 import com.squareup.javapoet.*;
 import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.code.Type;
@@ -52,7 +51,6 @@ public class TestableClassDevRoleGenerator {
             methodSpecs.add(buildFieldGetter(clazz, field));
             methodSpecs.add(buildFieldSetter(clazz, field));
         }
-        methodSpecs.add(buildStubbornFieldMethod(translator.getFields()));
 
         TypeSpec.Builder builder = TypeSpec.classBuilder(className)
             .addModifiers(Modifier.PUBLIC, Modifier.FINAL)
@@ -65,18 +63,6 @@ public class TestableClassDevRoleGenerator {
         return javaFile.toString();
     }
 
-    private MethodSpec buildStubbornFieldMethod(List<JCTree.JCVariableDecl> fields) {
-        List<String> fieldNames = new ArrayList<>();
-        for (JCTree.JCVariableDecl f : fields)  {
-            fieldNames.add("\"" + f.name.toString() + "\"");
-        }
-        return MethodSpec.methodBuilder(ConstPool.STUBBORN_FIELD_METHOD)
-            .addModifiers(Modifier.PUBLIC).addModifiers(Modifier.STATIC)
-            .addStatement("return new $T[]{" + StringUtil.join(fieldNames, ",") + "}", String.class)
-            .returns(ArrayTypeName.of(String.class))
-            .build();
-    }
-
     private MethodSpec buildFieldGetter(Symbol.ClassSymbol classElement, JCTree.JCVariableDecl field) {
         String fieldName = field.name.toString();
         return MethodSpec.methodBuilder(fieldName + ConstPool.TESTABLE_GET_METHOD_PREFIX)
diff --git a/src/main/java/com/alibaba/testable/processor/TestableProcessor.java b/src/main/java/com/alibaba/testable/processor/TestableProcessor.java
index 0c910db..ea00d7a 100644
--- a/src/main/java/com/alibaba/testable/processor/TestableProcessor.java
+++ b/src/main/java/com/alibaba/testable/processor/TestableProcessor.java
@@ -53,7 +53,7 @@ public class TestableProcessor extends BaseProcessor {
     private void createStaticNewClass() {
         if (!isStaticNewClassExist()) {
             try {
-                writeSourceFile(ConstPool.SN_PKG_CLS, new StaticNewClassGenerator(cx).fetch());
+                writeSourceFile(ConstPool.NE_PKG_CLS, new StaticNewClassGenerator(cx).fetch());
             } catch (IOException e) {
                 e.printStackTrace();
             }
@@ -62,8 +62,8 @@ public class TestableProcessor extends BaseProcessor {
 
     private boolean isStaticNewClassExist() {
         try {
-            FileObject staticNewClassFile = cx.filter.getResource(SOURCE_OUTPUT, ConstPool.SN_PKG,
-                ConstPool.SN_CLS + JAVA_POSTFIX);
+            FileObject staticNewClassFile = cx.filter.getResource(SOURCE_OUTPUT, ConstPool.NE_PKG,
+                ConstPool.NE_CLS + JAVA_POSTFIX);
             return isCompilingTestClass(staticNewClassFile) || staticNewClassFile.getLastModified() > 0;
         } catch (FilerException e) {
             return true;
diff --git a/src/main/java/com/alibaba/testable/translator/TestableClassDevRoleTranslator.java b/src/main/java/com/alibaba/testable/translator/TestableClassDevRoleTranslator.java
index 432a41f..51f3747 100644
--- a/src/main/java/com/alibaba/testable/translator/TestableClassDevRoleTranslator.java
+++ b/src/main/java/com/alibaba/testable/translator/TestableClassDevRoleTranslator.java
@@ -1,8 +1,6 @@
 package com.alibaba.testable.translator;
 
 import com.alibaba.testable.model.TestableContext;
-import com.alibaba.testable.translator.tree.TestableFieldAccess;
-import com.alibaba.testable.translator.tree.TestableMethodInvocation;
 import com.alibaba.testable.util.ConstPool;
 import com.sun.tools.javac.tree.JCTree;
 import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
@@ -11,8 +9,6 @@ import com.sun.tools.javac.util.List;
 import com.sun.tools.javac.util.ListBuffer;
 import com.sun.tools.javac.util.Name;
 
-import java.lang.reflect.Modifier;
-
 /**
  * Travel AST
  *
@@ -44,12 +40,6 @@ public class TestableClassDevRoleTranslator extends TreeTranslator {
         this.cx = cx;
     }
 
-    @Override
-    public void visitClassDef(JCTree.JCClassDecl jcClassDecl) {
-        super.visitClassDef(jcClassDecl);
-        jcClassDecl.mods.flags = jcClassDecl.mods.flags & (~Modifier.FINAL);
-    }
-
     /**
      * Record all methods
      */
@@ -61,46 +51,60 @@ public class TestableClassDevRoleTranslator extends TreeTranslator {
 
     /**
      * Case: new Demo()
+     * Case: member()
      */
     @Override
     public void visitExec(JCTree.JCExpressionStatement jcExpressionStatement) {
-        jcExpressionStatement.expr = checkAndExchangeNewOperation(jcExpressionStatement.expr);
+        jcExpressionStatement.expr = checkAndExchange(jcExpressionStatement.expr);
         super.visitExec(jcExpressionStatement);
     }
 
     /**
+     * For member method invocation break point
      * Case: call(new Demo())
      */
     @Override
     public void visitApply(JCTree.JCMethodInvocation tree) {
-        tree.args = checkAndExchangeNewOperation(tree.args);
+        tree.args = checkAndExchange(tree.args);
         super.visitApply(tree);
     }
 
+    /**
+     * Case: return new Demo()
+     * Case: return member()
+     */
+    @Override
+    public void visitReturn(JCTree.JCReturn jcReturn) {
+        jcReturn.expr = checkAndExchange(jcReturn.expr);
+        super.visitReturn(jcReturn);
+    }
+
     /**
      * Record all private fields
      * Case: Demo d = new Demo()
+     * Case: Demo d = member()
      */
     @Override
     public void visitVarDef(JCTree.JCVariableDecl jcVariableDecl) {
         if (isStubbornField(jcVariableDecl.mods)) {
             fields = fields.append(jcVariableDecl);
         }
-        jcVariableDecl.init = checkAndExchangeNewOperation(jcVariableDecl.init);
+        jcVariableDecl.init = checkAndExchange(jcVariableDecl.init);
         super.visitVarDef(jcVariableDecl);
     }
 
     /**
      * Case: new Demo().call()
+     * Case: member().call()
      */
     @Override
     public void visitSelect(JCTree.JCFieldAccess jcFieldAccess) {
-        jcFieldAccess.selected = checkAndExchangeNewOperation(jcFieldAccess.selected);
+        jcFieldAccess.selected = checkAndExchange(jcFieldAccess.selected);
         super.visitSelect(jcFieldAccess);
     }
 
     /**
-     * For break point
+     * For new operation break point
      */
     @Override
     public void visitNewClass(JCTree.JCNewClass jcNewClass) {
@@ -108,7 +112,7 @@ public class TestableClassDevRoleTranslator extends TreeTranslator {
     }
 
     /**
-     * For break point
+     * For new operation break point
      */
     @Override
     public void visitNewArray(JCTree.JCNewArray jcNewArray) {
@@ -120,43 +124,62 @@ public class TestableClassDevRoleTranslator extends TreeTranslator {
             mods.getFlags().contains(javax.lang.model.element.Modifier.FINAL);
     }
 
-    private List<JCTree.JCExpression> checkAndExchangeNewOperation(List<JCTree.JCExpression> args) {
+    private List<JCTree.JCExpression> checkAndExchange(List<JCTree.JCExpression> args) {
         if (args != null) {
             JCTree.JCExpression[] es = new JCTree.JCExpression[args.length()];
             for (int i = 0; i < args.length(); i++) {
-                es[i] = checkAndExchangeNewOperation(args.get(i));
+                es[i] = checkAndExchange(args.get(i));
             }
             return List.from(es);
         }
         return null;
     }
 
-    private JCTree.JCExpression checkAndExchangeNewOperation(JCTree.JCExpression expr) {
+    private JCTree.JCExpression checkAndExchange(JCTree.JCExpression expr) {
         if (isNewOperation(expr)) {
             JCTree.JCNewClass newClassExpr = (JCTree.JCNewClass)expr;
             Name className = ((JCTree.JCIdent)newClassExpr.clazz).name;
             try {
-                return getStaticNewCall(newClassExpr, className);
+                return getGlobalNewInvocation(newClassExpr, className);
             } catch (Exception e) {
                 e.printStackTrace();
             }
+        } else if (isMemberMethodInvocation(expr)) {
+            Name methodName = ((JCTree.JCIdent)((JCTree.JCMethodInvocation)expr).meth).name;
+            List<JCTree.JCExpression> args = ((JCTree.JCMethodInvocation)expr).args;
+            return getGlobalMemberInvocation(methodName, args);
         }
         return expr;
     }
 
+    private boolean isMemberMethodInvocation(JCTree.JCExpression expr) {
+        return expr != null && expr.getClass().equals(JCTree.JCMethodInvocation.class) &&
+            ((JCTree.JCMethodInvocation)expr).meth.getClass().equals(JCTree.JCIdent.class);
+    }
+
     private boolean isNewOperation(JCTree.JCExpression expr) {
         return expr != null && expr.getClass().equals(JCTree.JCNewClass.class);
     }
 
-    private TestableMethodInvocation getStaticNewCall(JCTree.JCNewClass newClassExpr, Name className) {
-        TestableFieldAccess snClass = new TestableFieldAccess(cx.treeMaker.Ident(cx.names.fromString(ConstPool.SN_PKG)),
-            cx.names.fromString(ConstPool.SN_CLS), null);
-        TestableFieldAccess snMethod = new TestableFieldAccess(snClass,
-            cx.names.fromString(ConstPool.SN_METHOD), null);
-        JCTree.JCExpression classType = new TestableFieldAccess(cx.treeMaker.Ident(className),
-            cx.names.fromString(ConstPool.TYPE_TO_CLASS), null);
+    private JCTree.JCMethodInvocation getGlobalNewInvocation(JCTree.JCNewClass newClassExpr, Name className) {
+        JCTree.JCFieldAccess snClass = cx.treeMaker.Select(cx.treeMaker.Ident(cx.names.fromString(ConstPool.NE_PKG)),
+            cx.names.fromString(ConstPool.NE_CLS));
+        JCTree.JCFieldAccess snMethod = cx.treeMaker.Select(snClass, cx.names.fromString(ConstPool.NE_NEW));
+        JCTree.JCExpression classType = cx.treeMaker.Select(cx.treeMaker.Ident(className),
+            cx.names.fromString(ConstPool.TYPE_TO_CLASS));
         ListBuffer<JCTree.JCExpression> args = ListBuffer.of(classType);
         args.addAll(newClassExpr.args);
-        return new TestableMethodInvocation(null, snMethod, args.toList());
+        return cx.treeMaker.Apply(List.<JCTree.JCExpression>nil(), snMethod, args.toList());
+    }
+
+    private JCTree.JCMethodInvocation getGlobalMemberInvocation(Name methodName, List<JCTree.JCExpression> param) {
+        JCTree.JCFieldAccess snClass = cx.treeMaker.Select(cx.treeMaker.Ident(cx.names.fromString(ConstPool.NE_PKG)),
+            cx.names.fromString(ConstPool.NE_CLS));
+        JCTree.JCFieldAccess snMethod = cx.treeMaker.Select(snClass, cx.names.fromString(ConstPool.NE_INK));
+        ListBuffer<JCTree.JCExpression> args = new ListBuffer();
+        args.add(cx.treeMaker.Ident(cx.names.fromString(ConstPool.REF_THIS)));
+        args.add(cx.treeMaker.Literal(methodName.toString()));
+        args.addAll(param);
+        return cx.treeMaker.Apply(List.<JCTree.JCExpression>nil(), snMethod, args.toList());
     }
 }
diff --git a/src/main/java/com/alibaba/testable/translator/TestableClassTestRoleTranslator.java b/src/main/java/com/alibaba/testable/translator/TestableClassTestRoleTranslator.java
index e0b678b..182e522 100644
--- a/src/main/java/com/alibaba/testable/translator/TestableClassTestRoleTranslator.java
+++ b/src/main/java/com/alibaba/testable/translator/TestableClassTestRoleTranslator.java
@@ -2,8 +2,6 @@ package com.alibaba.testable.translator;
 
 import com.alibaba.testable.model.TestLibType;
 import com.alibaba.testable.model.TestableContext;
-import com.alibaba.testable.translator.tree.TestableFieldAccess;
-import com.alibaba.testable.translator.tree.TestableMethodInvocation;
 import com.alibaba.testable.util.ConstPool;
 import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.tree.JCTree;
@@ -27,11 +25,11 @@ public class TestableClassTestRoleTranslator extends TreeTranslator {
     private static final String ANNOTATION_JUNIT5_SETUP = "org.junit.jupiter.api.BeforeEach";
     private static final String ANNOTATION_JUNIT5_TEST = "org.junit.jupiter.api.Test";
     private static final String TYPE_CLASS = "Class";
-    private static final String REF_THIS = "this";
     private final TestableContext cx;
     private String sourceClassName = "";
-    private ListBuffer<Name> sourceClassIns = new ListBuffer();
-    private List<String> stubbornFields = List.nil();
+    private final ListBuffer<Name> sourceClassIns = new ListBuffer();
+    private final ListBuffer<String> stubbornFields = new ListBuffer();
+    private final ListBuffer<Method> memberMethods = new ListBuffer();
 
     /**
      * MethodName -> (ResultType -> ParameterTypes)
@@ -44,10 +42,14 @@ public class TestableClassTestRoleTranslator extends TreeTranslator {
         this.sourceClassName = className;
         this.cx = cx;
         try {
-            stubbornFields = List.from(
-                (String[])Class.forName(pkgName + "." + className + ConstPool.TESTABLE)
-                .getMethod(ConstPool.STUBBORN_FIELD_METHOD)
-                .invoke(null));
+            Class<?> cls = Class.forName(pkgName + "." + className);
+            Field[] fields = cls.getDeclaredFields();
+            for (Field f : fields) {
+                if (Modifier.isFinal(f.getModifiers()) || Modifier.isPrivate(f.getModifiers())) {
+                    stubbornFields.add(f.getName());
+                }
+            }
+            memberMethods.addAll(Arrays.asList(cls.getDeclaredMethods()));
         } catch (Exception e) {
             e.printStackTrace();
         }
@@ -85,10 +87,9 @@ public class TestableClassTestRoleTranslator extends TreeTranslator {
         if (jcExpressionStatement.expr.getClass().equals(JCAssign.class) &&
             isAssignStubbornField((JCAssign)jcExpressionStatement.expr)) {
             JCAssign assign = (JCAssign)jcExpressionStatement.expr;
-            // TODO: Use treeMaker.Apply() and treeMaker.Select()
-            TestableFieldAccess stubbornSetter = new TestableFieldAccess(((JCFieldAccess)assign.lhs).selected,
-                getStubbornSetterMethodName(assign), null);
-            jcExpressionStatement.expr = new TestableMethodInvocation(null, stubbornSetter,
+            JCFieldAccess stubbornSetter = cx.treeMaker.Select(((JCFieldAccess)assign.lhs).selected,
+                getStubbornSetterMethodName(assign));
+            jcExpressionStatement.expr = cx.treeMaker.Apply(List.<JCExpression>nil(), stubbornSetter,
                 com.sun.tools.javac.util.List.of(assign.rhs));
         }
         super.visitExec(jcExpressionStatement);
@@ -103,12 +104,14 @@ public class TestableClassTestRoleTranslator extends TreeTranslator {
                     for (JCVariableDecl p : jcMethodDecl.params) {
                         args.add(cx.treeMaker.Select(p.vartype, cx.names.fromString(ConstPool.TYPE_TO_CLASS)));
                     }
-                    JCExpression retType = cx.treeMaker.Select(jcMethodDecl.restype, cx.names.fromString(ConstPool.TYPE_TO_CLASS));
+                    JCExpression retType = jcMethodDecl.restype == null ? null :
+                        cx.treeMaker.Select(jcMethodDecl.restype, cx.names.fromString(ConstPool.TYPE_TO_CLASS));
                     injectMethods.add(Pair.of(jcMethodDecl.name, Pair.of(retType, args.toList())));
                     break;
                 case ANNOTATION_JUNIT5_SETUP:
                     testSetupMethodName = jcMethodDecl.name.toString();
-                    jcMethodDecl.mods.annotations = removeAnnotation(jcMethodDecl.mods.annotations, ANNOTATION_JUNIT5_SETUP);
+                    jcMethodDecl.mods.annotations = removeAnnotation(jcMethodDecl.mods.annotations,
+                        ANNOTATION_JUNIT5_SETUP);
                     break;
                 case ANNOTATION_JUNIT5_TEST:
                     testLibType = TestLibType.JUnit5;
@@ -155,7 +158,7 @@ public class TestableClassTestRoleTranslator extends TreeTranslator {
     private JCExpression nameToExpression(String dotName) {
         String[] nameParts = dotName.split("\\.");
         JCExpression e = cx.treeMaker.Ident(cx.names.fromString(nameParts[0]));
-        for (int i = 1 ; i < nameParts.length ; i++) {
+        for (int i = 1; i < nameParts.length; i++) {
             e = cx.treeMaker.Select(e, cx.names.fromString(nameParts[i]));
         }
         return e;
@@ -164,7 +167,11 @@ public class TestableClassTestRoleTranslator extends TreeTranslator {
     private JCBlock testableSetupBlock() {
         ListBuffer<JCStatement> statements = new ListBuffer<>();
         for (Pair<Name, Pair<JCExpression, List<JCExpression>>> m : injectMethods.toList()) {
-            statements.append(toGlobalNewStatement(m));
+            if (isMemberMethod(m)) {
+                statements.append(toGlobalInvokeStatement(m));
+            } else {
+                statements.append(toGlobalNewStatement(m));
+            }
         }
         if (!testSetupMethodName.isEmpty()) {
             statements.append(cx.treeMaker.Exec(cx.treeMaker.Apply(List.<JCExpression>nil(),
@@ -173,20 +180,59 @@ public class TestableClassTestRoleTranslator extends TreeTranslator {
         return cx.treeMaker.Block(0, statements.toList());
     }
 
-    private JCStatement toGlobalNewStatement(
-        Pair<Name, Pair<JCExpression, List<JCExpression>>> m) {
-        JCExpression key = nameToExpression(ConstPool.NS_W_KEY);
-        JCExpression classType = m.snd.fst;
+    private boolean isMemberMethod(Pair<Name, Pair<JCExpression, List<JCExpression>>> m) {
+        for (Method method : memberMethods) {
+            if (method.getName().equals(m.fst.toString()) && parameterEquals(m.snd.snd, method.getParameterTypes())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean parameterEquals(List<JCExpression> injectMethodArgs, Class<?>[] memberMethodArgs) {
+        if (injectMethodArgs.length() != memberMethodArgs.length) {
+            return false;
+        }
+        for (int i = 0; i < injectMethodArgs.length(); i++) {
+            if (!memberMethodArgs[i].getName().equals(((JCFieldAccess)injectMethodArgs.get(i)).selected.type
+                .toString())) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private JCStatement toGlobalInvokeStatement(Pair<Name, Pair<JCExpression, List<JCExpression>>> m) {
+        JCExpression key = nameToExpression(ConstPool.NE_X_KEY);
+        JCExpression value = nameToExpression(ConstPool.NE_X_VAL);
+        JCExpression methodName = cx.treeMaker.Literal(m.fst.toString());
+        JCExpression thisIns = cx.treeMaker.Ident(cx.names.fromString(ConstPool.REF_THIS));
+        JCExpression returnClassType = m.snd.fst;
         JCExpression parameterTypes = cx.treeMaker.NewArray(cx.treeMaker.Ident(cx.names.fromString(TYPE_CLASS)),
             List.<JCExpression>nil(), m.snd.snd);
         JCNewClass keyClass = cx.treeMaker.NewClass(null, List.<JCExpression>nil(), key,
-            List.of(classType, parameterTypes), null);
-        JCExpression value = nameToExpression(ConstPool.NS_VAL);
-        JCExpression thisIns = cx.treeMaker.Ident(cx.names.fromString(REF_THIS));
+            List.of(methodName, parameterTypes), null);
+        JCNewClass valClass = cx.treeMaker.NewClass(null, List.<JCExpression>nil(), value,
+            List.of(thisIns, returnClassType), null);
+        JCExpression addInjectMethod = nameToExpression(ConstPool.NE_X_ADD);
+        JCMethodInvocation apply = cx.treeMaker.Apply(List.<JCExpression>nil(), addInjectMethod,
+            List.from(new JCExpression[] {keyClass, valClass}));
+        return cx.treeMaker.Exec(apply);
+    }
+
+    private JCStatement toGlobalNewStatement(Pair<Name, Pair<JCExpression, List<JCExpression>>> m) {
+        JCExpression key = nameToExpression(ConstPool.NE_W_KEY);
+        JCExpression value = nameToExpression(ConstPool.NE_W_VAL);
+        JCExpression classType = m.snd.fst;
+        JCExpression parameterTypes = cx.treeMaker.NewArray(cx.treeMaker.Ident(cx.names.fromString(TYPE_CLASS)),
+            List.<JCExpression>nil(), m.snd.snd);
+        JCExpression thisIns = cx.treeMaker.Ident(cx.names.fromString(ConstPool.REF_THIS));
         JCExpression methodName = cx.treeMaker.Literal(m.fst.toString());
+        JCNewClass keyClass = cx.treeMaker.NewClass(null, List.<JCExpression>nil(), key,
+            List.of(classType, parameterTypes), null);
         JCNewClass valClass = cx.treeMaker.NewClass(null, List.<JCExpression>nil(), value,
             List.of(thisIns, methodName), null);
-        JCExpression addInjectMethod = nameToExpression(ConstPool.NS_W_ADD);
+        JCExpression addInjectMethod = nameToExpression(ConstPool.NE_W_ADD);
         JCMethodInvocation apply = cx.treeMaker.Apply(List.<JCExpression>nil(), addInjectMethod,
             List.from(new JCExpression[] {keyClass, valClass}));
         return cx.treeMaker.Exec(apply);
diff --git a/src/main/java/com/alibaba/testable/translator/tree/TestableFieldAccess.java b/src/main/java/com/alibaba/testable/translator/tree/TestableFieldAccess.java
deleted file mode 100644
index 6acc56d..0000000
--- a/src/main/java/com/alibaba/testable/translator/tree/TestableFieldAccess.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package com.alibaba.testable.translator.tree;
-
-import com.sun.tools.javac.code.Symbol;
-import com.sun.tools.javac.tree.JCTree;
-import com.sun.tools.javac.util.Name;
-
-/**
- * @author flin
- */
-public class TestableFieldAccess extends JCTree.JCFieldAccess {
-
-    public TestableFieldAccess(JCExpression selected, Name name, Symbol sym) {
-        super(selected, name, sym);
-    }
-
-}
diff --git a/src/main/java/com/alibaba/testable/translator/tree/TestableMethodInvocation.java b/src/main/java/com/alibaba/testable/translator/tree/TestableMethodInvocation.java
deleted file mode 100644
index fd7a452..0000000
--- a/src/main/java/com/alibaba/testable/translator/tree/TestableMethodInvocation.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package com.alibaba.testable.translator.tree;
-
-import com.sun.tools.javac.tree.JCTree;
-import com.sun.tools.javac.util.List;
-
-/**
- * @author flin
- */
-public class TestableMethodInvocation extends JCTree.JCMethodInvocation {
-
-    public TestableMethodInvocation(List<JCExpression> typeargs, JCExpression meth, List<JCExpression> args) {
-        super(typeargs, meth, args);
-    }
-
-}
diff --git a/src/main/java/com/alibaba/testable/util/ConstPool.java b/src/main/java/com/alibaba/testable/util/ConstPool.java
index bdcc779..c280694 100644
--- a/src/main/java/com/alibaba/testable/util/ConstPool.java
+++ b/src/main/java/com/alibaba/testable/util/ConstPool.java
@@ -8,16 +8,20 @@ public final class ConstPool {
     public static final String CONSTRUCTOR_NAME = "<init>";
     public static final String TYPE_VOID = "void";
     public static final String TESTABLE = "Testable";
-    public static final String SN_PKG = "n";
-    public static final String SN_CLS = "e";
-    public static final String SN_METHOD = "w";
-    public static final String SN_PKG_CLS = "n.e";
-    public static final String NS_W_KEY = "n.e.wk";
-    public static final String NS_VAL = "n.e.v";
-    public static final String NS_W_ADD = "n.e.wa";
-    public static final String STUBBORN_FIELD_METHOD = "stubbornField";
+    public static final String NE_PKG = "n";
+    public static final String NE_CLS = "e";
+    public static final String NE_NEW = "w";
+    public static final String NE_INK = "x";
+    public static final String NE_PKG_CLS = "n.e";
+    public static final String NE_W_KEY = "n.e.wk";
+    public static final String NE_X_KEY = "n.e.xk";
+    public static final String NE_W_VAL = "n.e.wv";
+    public static final String NE_X_VAL = "n.e.xv";
+    public static final String NE_W_ADD = "n.e.wa";
+    public static final String NE_X_ADD = "n.e.xa";
     public static final String TESTABLE_GET_METHOD_PREFIX = "TestableGet";
     public static final String TESTABLE_SET_METHOD_PREFIX = "TestableSet";
     public static final String TYPE_TO_CLASS = "class";
+    public static final String REF_THIS = "this";
 
 }
diff --git a/src/main/resources/e.java b/src/main/resources/e.java
index 4e5d4b6..2e79927 100644
--- a/src/main/resources/e.java
+++ b/src/main/resources/e.java
@@ -57,33 +57,46 @@ public final class e {
   }
 
   /**
-   * value for contructor and method pool
+   * value for contructor pool
    */
-  public static class v {
+  public static class wv {
     public Object o;  // object which provides substitution
     public String m;  // substitutional method name
 
-    public v(Object o, String m) {
+    public wv(Object o, String m) {
       this.o = o;
       this.m = m;
     }
   }
 
-  private static Map<wk, v> wp = new HashMap<>();
-  private static Map<xk, v> xp = new HashMap<>();
+  /**
+   * value for member method pool
+   */
+  public static class xv {
+    public Object o;  // object which provides substitution
+    public Class c;   // method return type
+
+    public xv(Object o, Class c) {
+      this.o = o;
+      this.c = c;
+    }
+  }
+
+  private static Map<wk, wv> wp = new HashMap<>();
+  private static Map<xk, xv> xp = new HashMap<>();
 
   /**
    * add item to contructor pool
    */
-  public static void wa(wk k, v vv) {
-    wp.put(k, vv);
+  public static void wa(wk k, wv v) {
+    wp.put(k, v);
   }
 
   /**
    * add item to method pool
    */
-  public static void xa(xk k, v vv) {
-    xp.put(k, vv);
+  public static void xa(xk k, xv v) {
+    xp.put(k, v);
   }
 
   /**
@@ -96,7 +109,7 @@ public final class e {
     }
     if (!wp.isEmpty()) {
       try {
-        Pair<wk, v> p = gwp(new wk(ct, cs));
+        Pair<wk, wv> p = gwp(new wk(ct, cs));
         if (p != null) {
           Method m = p.snd.o.getClass().getDeclaredMethod(p.snd.m, p.fst.a);
           m.setAccessible(true);
@@ -120,24 +133,25 @@ public final class e {
   /**
    * subsitituion entry for member call
    */
-  public static Object x(Object obj, String method, Object... as) {
+  public static <T> T x(Object obj, String method, Object... as) {
     Class[] cs = gcs(as);
     if (!xp.isEmpty()) {
       try {
-        Pair<xk, v> p = gxp(new xk(method, cs));
+        Pair<xk, xv> p = gxp(new xk(method, cs));
         if (p != null) {
-          Method m = p.snd.o.getClass().getDeclaredMethod(p.snd.m, p.fst.a);
+          Method m = p.snd.o.getClass().getDeclaredMethod(p.fst.m, p.fst.a);
           m.setAccessible(true);
-          return m.invoke(p.snd.o, as);
+          return (T)m.invoke(p.snd.o, as);
         }
       } catch (Exception e) {
         return null;
       }
     }
     try {
-      Method m = gm(obj.getClass().getMethods(), cs);
+      Method m = gm(obj.getClass().getDeclaredMethods(), method, cs);
       if (m != null) {
-        return m.invoke(obj, as);
+        m.setAccessible(true);
+        return (T)m.invoke(obj, as);
       }
     } catch (Exception e) {
       return null;
@@ -159,9 +173,9 @@ public final class e {
   /**
    * get method by parameter matching
    */
-  private static Method gm(Method[] methods, Class[] cs) {
+  private static Method gm(Method[] methods, String name, Class[] cs) {
     for (Method m : methods) {
-      if (te(m.getParameterTypes(), cs)) {
+      if (m.getName().equals(name) && te(m.getParameterTypes(), cs)) {
         return m;
       }
     }
@@ -171,7 +185,7 @@ public final class e {
   /**
    * get from method pool by key
    */
-  private static Pair<xk, v> gxp(xk k1) {
+  private static Pair<xk, xv> gxp(xk k1) {
     for (xk k2 : xp.keySet()) {
       if (k1.m.equals(k2.m) && te(k2.a, k1.a)) {
         return Pair.of(k2, xp.get(k2));
@@ -195,7 +209,7 @@ public final class e {
   /**
    * get from contructor pool by key
    */
-  private static Pair<wk, v> gwp(wk k1) {
+  private static Pair<wk, wv> gwp(wk k1) {
     for (wk k2 : wp.keySet()) {
       if (k1.c.equals(k2.c) && te(k2.a, k1.a)) {
         return Pair.of(k2, wp.get(k2));