static <T> int listSizeInBytes(WriteBuffer.Writer<T> writer, List<T> values) {
    int sizeInBytes = 5;
    for (T value : values) {
      sizeInBytes += writer.sizeInBytes(value);
    }
    return sizeInBytes;
  }
Encoding overhead is thrift type plus 32-bit length prefix
zipkin/src/main/java/zipkin2/internal/ThriftCodec.java