public List<Span> decodeList(ByteBuffer spans) {
    try {
      return listSpansAdapter.fromJson(JsonReader.of(Okio.buffer(new ByteBufferSource(spans))));
    } catch (IOException e) {
      throw new AssertionError(e); // no I/O
    }
  }
Read-only json adapters resurrected from before we switched to Java 6 as storage components can
be Java 7+
benchmarks/src/test/java/zipkin2/codec/MoshiSpanDecoder.java