private com.google.protobuf.MapField<java.lang.String, java.lang.String>
      internalGetAnnotations() {
    if (annotations_ == null) {
      return com.google.protobuf.MapField.emptyMapField(AnnotationsDefaultEntryHolder.defaultEntry);
    }
    return annotations_;
  }
<pre>
Output only. The time at which this resource will be purged.
This field is not used.
</pre>

<code>.google.protobuf.Timestamp expire_time = 12 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-speech/proto-google-cloud-speech-v1p1beta1/src/main/java/com/google/cloud/speech/v1p1beta1/CustomClass.java