Class DummySerializerInstance

Object
org.apache.spark.serializer.SerializerInstance
org.apache.spark.serializer.DummySerializerInstance

@Private public final class DummySerializerInstance extends SerializerInstance
Unfortunately, we need a serializer instance in order to construct a DiskBlockObjectWriter. Our shuffle write path doesn't actually use this serializer (since we end up calling the `write() OutputStream methods), but DiskBlockObjectWriter still calls some methods on it. To work around this, we pass a dummy no-op serializer.