@Test void decoderForListMessage_json_v2_singleItem() {
    assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(() -> {
      byte[] message = SpanBytesEncoder.JSON_V2.encode(span1);
      SpanBytesDecoderDetector.decoderForListMessage(message);
    });
  }
Single-element reads were for legacy non-list encoding. Don't add new code that does this
zipkin/src/test/java/zipkin2/SpanBytesDecoderDetectorTest.java