diff --git a/src/test/java/xyz/zhouxy/plusone/commons/collection/CollectionToolsTests.java b/src/test/java/xyz/zhouxy/plusone/commons/collection/CollectionToolsTests.java
index 0b54e2d..bcb53a6 100644
--- a/src/test/java/xyz/zhouxy/plusone/commons/collection/CollectionToolsTests.java
+++ b/src/test/java/xyz/zhouxy/plusone/commons/collection/CollectionToolsTests.java
@@ -1,3 +1,19 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.
+ */
+
 package xyz.zhouxy.plusone.commons.collection;
 
 import static org.junit.jupiter.api.Assertions.assertFalse;
diff --git a/src/test/java/xyz/zhouxy/plusone/commons/util/EnumToolsTests.java b/src/test/java/xyz/zhouxy/plusone/commons/util/EnumToolsTests.java
index a4c83fb..d4442cd 100644
--- a/src/test/java/xyz/zhouxy/plusone/commons/util/EnumToolsTests.java
+++ b/src/test/java/xyz/zhouxy/plusone/commons/util/EnumToolsTests.java
@@ -1,3 +1,19 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.
+ */
+
 package xyz.zhouxy.plusone.commons.util;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
diff --git a/src/test/java/xyz/zhouxy/plusone/commons/util/IdGeneratorTests.java b/src/test/java/xyz/zhouxy/plusone/commons/util/IdGeneratorTests.java
index 55edba9..7447e48 100644
--- a/src/test/java/xyz/zhouxy/plusone/commons/util/IdGeneratorTests.java
+++ b/src/test/java/xyz/zhouxy/plusone/commons/util/IdGeneratorTests.java
@@ -1,3 +1,19 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.
+ */
+
 package xyz.zhouxy.plusone.commons.util;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
diff --git a/src/test/java/xyz/zhouxy/plusone/commons/util/RandomToolsTests.java b/src/test/java/xyz/zhouxy/plusone/commons/util/RandomToolsTests.java
index fcf5f44..2f63bc6 100644
--- a/src/test/java/xyz/zhouxy/plusone/commons/util/RandomToolsTests.java
+++ b/src/test/java/xyz/zhouxy/plusone/commons/util/RandomToolsTests.java
@@ -1,3 +1,19 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.
+ */
+
 package xyz.zhouxy.plusone.commons.util;
 
 import static org.junit.jupiter.api.Assertions.assertAll;