docs: @SuppressWarnings("unchecked")
      public static <T> T copy(Configuration conf, T src, T dst) throws IOException {
          CopyInCopyOutBuffer buffer = cloneBuffers.get();
          buffer.outBuffer.reset();
          SerializationFactory factory = getFactory(conf);
          Class<T> cls = (Class<T>) src.getClass();
          Serializer<T> serializer = factory.getSerializer(cls);
          serializer.open(buffer.outBuffer);
          serializer.serialize(src);
          buffer.moveData();
          Deserializer<T> deserializer = factory.getDeserializer(cls);
          deserializer.open(buffer.inBuffer);
          dst = deserializer.deserialize(dst);
          return dst;
      }