private com.google.protobuf.SingleFieldBuilderV3<
              com.google.protobuf.Timestamp,
              com.google.protobuf.Timestamp.Builder,
              com.google.protobuf.TimestampOrBuilder>
          getDwellStartTimeFieldBuilder() {
        if (dwellStartTimeBuilder_ == null) {
          dwellStartTimeBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.protobuf.Timestamp,
                  com.google.protobuf.Timestamp.Builder,
                  com.google.protobuf.TimestampOrBuilder>(
                  getDwellStartTime(), getParentForChildren(), isClean());
          dwellStartTime_ = null;
        }
        return dwellStartTimeBuilder_;
      }
<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