private com.google.protobuf.SingleFieldBuilderV3<
            com.google.protobuf.Duration,
            com.google.protobuf.Duration.Builder,
            com.google.protobuf.DurationOrBuilder>
        getTtlFieldBuilder() {
      if (ttlBuilder_ == null) {
        ttlBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.protobuf.Duration,
                com.google.protobuf.Duration.Builder,
                com.google.protobuf.DurationOrBuilder>(getTtl(), getParentForChildren(), isClean());
        ttl_ = null;
      }
      return ttlBuilder_;
    }
<pre>
The duration for which all media assets, associated metadata, and search
documents can exist. If not set, then it will using the default ttl in the
parent corpus resource.
</pre>

<code>.google.protobuf.Duration ttl = 2;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/Asset.java