Example for using tracing extension and messages about sdk-rust HOT 2 OPEN

 let builder = cloudevents::EventBuilderV10::new()
      .id(Ulid::new())
      .source(SOURCE_NAME)
      .ty(EXAMPLE_EVENT_TYPE)
      .time(chrono::Utc::now())
      .subject(example_object.id)
      .data(
          mime::APPLICATION_OCTET_STREAM.to_string(),
          bincode::serialize(&example_object)?,
      )

  let span = tracing::Span::current();
  let otel_context = span.context();
  let span = otel_context.span();
  let span_context = span.span_context();
  if span_context.is_sampled() {
      let trace_id = span_context.trace_id().to_bytes();
      let span_id = span_context.span_id().to_bytes();
      let trace_flags = span_context.trace_flags().to_u8();
      let trace_id_hex = hex::encode(trace_id);
      let span_id_hex = hex::encode(span_id);
      let traceparent = format!("00-{}-{}-{:02x}", trace_id_hex, span_id_hex, trace_flags);
      builder = builder.extension("traceparent", traceparent);
  }
  let example_event = builder.build()?;