public static com.google.cloud.translate.v3.Example getDefaultInstance() {
    return DEFAULT_INSTANCE;
  }
<pre>
Output only. Usage of the sentence pair. Options are TRAIN|VALIDATION|TEST.
</pre>

<code>string usage = 4 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

@param value The bytes for usage to set.
@return This builder for chaining.
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/Example.java