public com.google.devtools.cloudtrace.v2.TruncatableStringOrBuilder
          getSourceVersionOrBuilder() {
        if (sourceVersionBuilder_ != null) {
          return sourceVersionBuilder_.getMessageOrBuilder();
        } else {
          return sourceVersion_ == null
              ? com.google.devtools.cloudtrace.v2.TruncatableString.getDefaultInstance()
              : sourceVersion_;
        }
      }
<pre>
The version of the deployed source code (up to 128 bytes).
</pre>

<code>.google.devtools.cloudtrace.v2.TruncatableString source_version = 7;</code>
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/StackTrace.java