public Builder setSourceVersion(com.google.devtools.cloudtrace.v2.TruncatableString value) {
        if (sourceVersionBuilder_ == null) {
          if (value == null) {
            throw new NullPointerException();
          }
          sourceVersion_ = value;
        } else {
          sourceVersionBuilder_.setMessage(value);
        }
        bitField0_ |= 0x00000040;
        onChanged();
        return this;
      }
<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