public com.google.protobuf.TimestampOrBuilder getDwellStartTimeOrBuilder() {
        if (dwellStartTimeBuilder_ != null) {
          return dwellStartTimeBuilder_.getMessageOrBuilder();
        } else {
          return dwellStartTime_ == null
              ? com.google.protobuf.Timestamp.getDefaultInstance()
              : dwellStartTime_;
        }
      }
<pre>
The beginning time when a dwelling object has been identified in a zone.
</pre>

<code>.google.protobuf.Timestamp dwell_start_time = 3;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/OccupancyCountingPredictionResult.java