missing license header
diff --git a/src/main/org/apache/tools/ant/types/resources/AppendableResourceCollection.java b/src/main/org/apache/tools/ant/types/resources/AppendableResourceCollection.java
index d85054a..cc7bd53 100644
--- a/src/main/org/apache/tools/ant/types/resources/AppendableResourceCollection.java
+++ b/src/main/org/apache/tools/ant/types/resources/AppendableResourceCollection.java
@@ -1,3 +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
+ *
+ *      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 org.apache.tools.ant.types.resources;
 
 import org.apache.tools.ant.BuildException;