Add missing license header
diff --git a/log4j-api-kotlin/src/main/kotlin/org/apache/logging/log4j/kotlin/Suppliers.kt b/log4j-api-kotlin/src/main/kotlin/org/apache/logging/log4j/kotlin/Suppliers.kt
index 57bbf55..b98e9db 100644
--- a/log4j-api-kotlin/src/main/kotlin/org/apache/logging/log4j/kotlin/Suppliers.kt
+++ b/log4j-api-kotlin/src/main/kotlin/org/apache/logging/log4j/kotlin/Suppliers.kt
@@ -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.logging.log4j.kotlin
import org.apache.logging.log4j.util.Supplier
