private com.google.protobuf.SingleFieldBuilderV3<
              com.google.devtools.cloudtrace.v2.TruncatableString,
              com.google.devtools.cloudtrace.v2.TruncatableString.Builder,
              com.google.devtools.cloudtrace.v2.TruncatableStringOrBuilder>
          getSourceVersionFieldBuilder() {
        if (sourceVersionBuilder_ == null) {
          sourceVersionBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.devtools.cloudtrace.v2.TruncatableString,
                  com.google.devtools.cloudtrace.v2.TruncatableString.Builder,
                  com.google.devtools.cloudtrace.v2.TruncatableStringOrBuilder>(
                  getSourceVersion(), getParentForChildren(), isClean());
          sourceVersion_ = null;
        }
        return sourceVersionBuilder_;
      }
<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