private void maybeForceBuilderInitialization() {
        if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {
          getFunctionNameFieldBuilder();
          getOriginalFunctionNameFieldBuilder();
          getFileNameFieldBuilder();
          getLoadModuleFieldBuilder();
          getSourceVersionFieldBuilder();
        }
      }
<pre>
Represents a single stack frame in a stack trace.
</pre>

Protobuf type {@code google.devtools.cloudtrace.v2.StackTrace.StackFrame}
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/StackTrace.java