diff --git a/core/src/index/unittest/Helper.h b/core/src/index/unittest/Helper.h
index 6f043ce0e315abc1c9b2b39148bc09f9bbdd03b3..d11a484c0334c1f399e189794fedbfe426b7f549 100644
--- a/core/src/index/unittest/Helper.h
+++ b/core/src/index/unittest/Helper.h
@@ -16,6 +16,7 @@
 // under the License.
 
 #include <memory>
+#include <string>
 
 #include "knowhere/index/vector_index/IndexGPUIVF.h"
 #include "knowhere/index/vector_index/IndexGPUIVFPQ.h"
@@ -116,4 +117,4 @@ class TestGpuIndexBase : public ::testing::Test {
     TearDown() override {
         knowhere::FaissGpuResourceMgr::GetInstance().Free();
     }
-};
\ No newline at end of file
+};
diff --git a/core/src/index/unittest/test_customized_index.cpp b/core/src/index/unittest/test_customized_index.cpp
index 29809b6f3a8034a3a7dbc72885b92dd8d33722be..10b635043ae355e84907c96cadf6a703ff55ad45 100644
--- a/core/src/index/unittest/test_customized_index.cpp
+++ b/core/src/index/unittest/test_customized_index.cpp
@@ -1,6 +1,20 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
 //
-// Created by link on 2019/10/17.
+//   http://www.apache.org/licenses/LICENSE-2.0
 //
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
 #include <gtest/gtest.h>
 
 #include "unittest/Helper.h"
diff --git a/core/unittest/wrapper/test_hybrid_index.cpp b/core/unittest/wrapper/test_hybrid_index.cpp
index cbd536d7afc05b87cf3a4f5a57fb32e1c890e3c6..757d5b20988e56c6da4e1359868290f7fe78eae2 100644
--- a/core/unittest/wrapper/test_hybrid_index.cpp
+++ b/core/unittest/wrapper/test_hybrid_index.cpp
@@ -28,7 +28,7 @@ using ::testing::Values;
 using ::testing::Combine;
 
 class KnowhereHybrid
- : public DataGenBase, public ::testing::Test {
+    : public DataGenBase, public ::testing::Test {
  protected:
     void SetUp() override {
         knowhere::FaissGpuResourceMgr::GetInstance().InitDevice(DEVICEID, PINMEM, TEMPMEM, RESNUM);
@@ -38,7 +38,6 @@ class KnowhereHybrid
         nq = 100;
         k = 100;
         GenData(dim, nb, nq, xb, xq, ids, k, gt_ids, gt_dis);
-
     }
 
     void TearDown() override {
@@ -130,4 +129,5 @@ TEST_F(KnowhereHybrid, test_interface) {
         }
     }
 }
+
 #endif
diff --git a/core/unittest/wrapper/utils.cpp b/core/unittest/wrapper/utils.cpp
index 7074823683ddcab4a54b5f21a1e6cdf1cf9e176f..445b7a2de6f158dc1cd34aace4a096c383401130 100644
--- a/core/unittest/wrapper/utils.cpp
+++ b/core/unittest/wrapper/utils.cpp
@@ -86,5 +86,4 @@ DataGenBase::AssertResult(const std::vector<int64_t>& ids, const std::vector<flo
                   << ", match: " << match
                   << ", total: " << nq * k
                   << std::endl;
-
 }
diff --git a/core/unittest/wrapper/utils.h b/core/unittest/wrapper/utils.h
index 458c50ccb2b7cd728b939e4f0908c733e51c60c5..b895b599e026a5cf77717f485cdb0744ddfa4617 100644
--- a/core/unittest/wrapper/utils.h
+++ b/core/unittest/wrapper/utils.h
@@ -70,13 +70,6 @@ class DataGenBase {
     std::vector<float> gt_dis;
 };
 
-namespace {
-
-namespace ms = milvus::engine;
-namespace kw = knowhere;
-
-} // namespace
-
 class ParamGenerator {
  public:
     static ParamGenerator& GetInstance() {