public com.google.protobuf.DurationOrBuilder getHeartbeatIntervalOrBuilder() {
        if (heartbeatIntervalBuilder_ != null) {
          return heartbeatIntervalBuilder_.getMessageOrBuilder();
        } else {
          return heartbeatInterval_ == null
              ? com.google.protobuf.Duration.getDefaultInstance()
              : heartbeatInterval_;
        }
      }
<pre>
The maximum duration of server silence before the client determines the
server unreachable.

The client must either receive an `Event` update or a heart beat message
before this duration expires; otherwise, the client will automatically
cancel the current connection and retry.
</pre>

<code>.google.protobuf.Duration heartbeat_interval = 5;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/ReceiveEventsRequest.java