public com.google.devtools.cloudtrace.v2.TruncatableString.Builder getStringValueBuilder() {
      return getStringValueFieldBuilder().getBuilder();
    }
<pre>
A string up to 256 bytes long.
</pre>

<code>.google.devtools.cloudtrace.v2.TruncatableString string_value = 1;</code>
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/AttributeValue.java