public com.google.devtools.cloudtrace.v2.StackTrace.Builder getStackTraceBuilder() {
      bitField0_ |= 0x00000080;
      onChanged();
      return getStackTraceFieldBuilder().getBuilder();
    }
<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