byte[] write(Span onlySpan) {
    int sizeOfValue = SPAN.sizeOfValue(onlySpan);
    byte[] result = new byte[sizeOfLengthDelimitedField(sizeOfValue)];
    writeSpan(onlySpan, sizeOfValue, WriteBuffer.wrap(result));
    return result;
  }
Encodes per ListOfSpans data wireType, where field one is repeated spans
zipkin/src/main/java/zipkin2/internal/Proto3SpanWriter.java