Comment for ByteArrayOutputStreamWriter

src/main/java/com/nvidia/spark/rapids/jni/kudo/ByteArrayOutputStreamWriter.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright (c) 2025, NVIDIA CORPORATION.
+ *
+ * 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
+ *
+ *     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 com.nvidia.spark.rapids.jni.kudo;
 
 import static java.lang.Math.toIntExact;
@@ -9,6 +25,10 @@
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 
+/**
+ * Adapter class which helps to save memory copy when shuffle manager uses {@link ByteArrayOutputStream} during
+ * serialization.
+ */
 public class ByteArrayOutputStreamWriter implements DataWriter {
   private static final Method ENSURE_CAPACITY;
   private static final Field BUF;