public Builder clearDwellStartTime() {
        bitField0_ = (bitField0_ & ~0x00000004);
        dwellStartTime_ = null;
        if (dwellStartTimeBuilder_ != null) {
          dwellStartTimeBuilder_.dispose();
          dwellStartTimeBuilder_ = null;
        }
        onChanged();
        return this;
      }
<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