public com.google.devtools.cloudtrace.v2.StackTraceOrBuilder getStackTraceOrBuilder() {
      if (stackTraceBuilder_ != null) {
        return stackTraceBuilder_.getMessageOrBuilder();
      } else {
        return stackTrace_ == null
            ? com.google.devtools.cloudtrace.v2.StackTrace.getDefaultInstance()
            : stackTrace_;
      }
    }
<pre>
Stack trace captured at the start of the span.
</pre>

<code>.google.devtools.cloudtrace.v2.StackTrace stack_trace = 8;</code>
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/Span.java