SOLR-14749: Add missing license header.
diff --git a/solr/core/src/java/org/apache/solr/cluster/events/ClusterEventProducerBase.java b/solr/core/src/java/org/apache/solr/cluster/events/ClusterEventProducerBase.java
index 9f9d0d2..4bd400d 100644
--- a/solr/core/src/java/org/apache/solr/cluster/events/ClusterEventProducerBase.java
+++ b/solr/core/src/java/org/apache/solr/cluster/events/ClusterEventProducerBase.java
@@ -1,3 +1,19 @@
+/*
+ * 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
+ *
+ * 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.
+ */
package org.apache.solr.cluster.events;
import org.apache.solr.common.util.IOUtils;
diff --git a/solr/core/src/java/org/apache/solr/cluster/events/impl/ClusterEventProducerFactory.java b/solr/core/src/java/org/apache/solr/cluster/events/impl/ClusterEventProducerFactory.java
index 6d14817..17f769b 100644
--- a/solr/core/src/java/org/apache/solr/cluster/events/impl/ClusterEventProducerFactory.java
+++ b/solr/core/src/java/org/apache/solr/cluster/events/impl/ClusterEventProducerFactory.java
@@ -1,3 +1,19 @@
+/*
+ * 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
+ *
+ * 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.
+ */
package org.apache.solr.cluster.events.impl;
import org.apache.solr.api.ContainerPluginsRegistry;