diff --git a/hugegraph-common/src/test/java/com/baidu/hugegraph/testutil/WhiteboxTest.java b/hugegraph-common/src/test/java/com/baidu/hugegraph/testutil/WhiteboxTest.java
index 9afbd117..6375c0dc 100644
--- a/hugegraph-common/src/test/java/com/baidu/hugegraph/testutil/WhiteboxTest.java
+++ b/hugegraph-common/src/test/java/com/baidu/hugegraph/testutil/WhiteboxTest.java
@@ -56,7 +56,7 @@ public void testGetInternalState() {
         Test1 test1 = newTest();
         Assert.assertEquals(1, Whitebox.getInternalState(test1, "ivalue"));
         Assert.assertEquals(2f, Whitebox.getInternalState(test1,
-                                                          "test2.fvalue"));
+                                                          "test2.finalValue"));
         Assert.assertEquals("3",  Whitebox.getInternalState(test1,
                                                             "test2.test3.str"));
 
@@ -65,7 +65,7 @@ public void testGetInternalState() {
         });
 
         Assert.assertThrows(RuntimeException.class, () -> {
-            Whitebox.getInternalState(test1, "test2.fvalue2");
+            Whitebox.getInternalState(test1, "test2.valueNotExist");
         });
     }
 
@@ -77,9 +77,9 @@ public void testSetInternalState() {
         Assert.assertEquals(11, Whitebox.getInternalState(test1, "ivalue"));
         Assert.assertEquals(11, test1.ivalue);
 
-        Whitebox.setInternalState(test1, "test2.fvalue", 22f);
+        Whitebox.setInternalState(test1, "test2.finalValue", 22f);
         Assert.assertEquals(22f, Whitebox.getInternalState(test1,
-                                                          "test2.fvalue"));
+                                                          "test2.finalValue"));
 
         Whitebox.setInternalState(test1, "test2.test3.str", "33");
         Assert.assertEquals("33",  Whitebox.getInternalState(test1,
@@ -90,23 +90,40 @@ public void testSetInternalState() {
         });
 
         Assert.assertThrows(RuntimeException.class, () -> {
-            Whitebox.setInternalState(test1, "test2.fvalue2", 22f);
+            Whitebox.setInternalState(test1, "test2.valueNotExist", 22f);
         });
 
         Assert.assertThrows(RuntimeException.class, () -> {
-            Whitebox.setInternalState(test1, "test2.fvalue", 22d);
+            Whitebox.setInternalState(test1, "test2.finalValue", 22d);
+        });
+
+        Assert.assertThrows(RuntimeException.class, () -> {
+            test1.test2 = null;
+            Whitebox.setInternalState(test1, "test2.finalValue", 22f);
+        }, e -> {
+            Assert.assertContains("Can't set value on null field",
+                                  e.getMessage());
         });
     }
 
     @Test
     public void testSetInternalFinalState() {
         Test1 test1 = newTest();
-        Assert.assertEquals(1, test1.ivalueFinal);
+        Assert.assertEquals(1, test1.finalValue);
+
+        Whitebox.setInternalState(test1, "finalValue", 2);
+        Assert.assertEquals(2, Whitebox.getInternalState(test1, "finalValue"));
+
+        Whitebox.setInternalState(test1, "finalValue", 3);
+        Assert.assertEquals(3, Whitebox.getInternalState(test1, "finalValue"));
+
+        Whitebox.setInternalState(test1, "test2.finalValue", 22f);
+        Assert.assertEquals(22f, Whitebox.getInternalState(test1,
+                                                           "test2.finalValue"));
 
-        Whitebox.setInternalState(test1, "ivalueFinal", 2);
-        Assert.assertEquals(2, Whitebox.getInternalState(test1, "ivalueFinal"));
         // FIXME: seems don't take effect!!!
-        Assert.assertEquals(1, test1.ivalueFinal);
+        Assert.assertEquals(1, test1.finalValue);
+        Assert.assertEquals(2f, test1.test2.finalValue, 0f);
     }
 
     @Test
@@ -173,7 +190,7 @@ private static class Test1 {
         private static int staticValue = 1;
 
         private int ivalue = 1;
-        private final int ivalueFinal = 1;
+        private final int finalValue = 1;
 
         private Test2 test2;
         private TestSubClass test4;
@@ -211,11 +228,11 @@ private static int throwfunc2() throws Exception {
     private static class Test2 {
 
         private static int staticValue = 2;
-        private final float fvalue = 2;
+        private final float finalValue = 2f;
         private Test3 test3;
 
         private float value() {
-            return this.fvalue;
+            return this.finalValue;
         }
 
         private <T> T value(T o) {