brave-instrumentation-dubbo some exception

[jiangjunjieabc]

if (kind.equals(Kind.CLIENT)) {
// When A service invoke B service, then B service then invoke C service, the parentId of the
// C service span is A when read from invocation.getAttachments(). This is because
// AbstractInvoker adds attachments via RpcContext.getContext(), not the invocation.
// See org.apache.dubbo.rpc.protocol.AbstractInvoker(line 141) from v2.7.3
Map<String, String> attachments = RpcContext.getContext().getAttachments();
DubboClientRequest clientRequest = new DubboClientRequest(invoker, invocation, attachments);
request = clientRequest;
span = clientHandler.handleSendWithParent(clientRequest, invocationContext);
} else {
DubboServerRequest serverRequest = new DubboServerRequest(invoker, invocation);
request = serverRequest;
span = serverHandler.handleReceive(serverRequest);
}

boolean isSynchronous = true;
Scope scope = currentTraceContext.newScope(span.context());
Result result = null;
Throwable error = null;
try {
  result = invoker.invoke(invocation);

当我执行到这里，我在生产者那边无法获取到【traceId】 或者 【spanId】，我打断点后发现，invocation的attachments并不包含这些内容（B3）,如果我在这里为invocation设置attachments，生产者那边就可以正常读取，否则不能

[jiangjunjieabc]

付下版本。这边用的版本为 brave-instrumentation-dubbo 5.13.9