@java.lang.Override
    public com.google.protobuf.Duration getTtl() {
      if (ttlBuilder_ == null) {
        if (expirationCase_ == 14) {
          return (com.google.protobuf.Duration) expiration_;
        }
        return com.google.protobuf.Duration.getDefaultInstance();
      } else {
        if (expirationCase_ == 14) {
          return ttlBuilder_.getMessage();
        }
        return com.google.protobuf.Duration.getDefaultInstance();
      }
    }
<pre>
Input only. The time-to-live (TTL) or duration for the subscription. If
unspecified or set to `0`, uses the maximum possible duration.
</pre>

<code>.google.protobuf.Duration ttl = 14 [(.google.api.field_behavior) = INPUT_ONLY];</code>

@return The ttl.
java-workspaceevents/proto-google-cloud-workspaceevents-v1/src/main/java/com/google/apps/events/subscriptions/v1/Subscription.java