private com.google.protobuf.SingleFieldBuilderV3<
            com.google.protobuf.Timestamp,
            com.google.protobuf.Timestamp.Builder,
            com.google.protobuf.TimestampOrBuilder>
        getStartTimeFieldBuilder() {
      if (startTimeBuilder_ == null) {
        startTimeBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.protobuf.Timestamp,
                com.google.protobuf.Timestamp.Builder,
                com.google.protobuf.TimestampOrBuilder>(
                getStartTime(), getParentForChildren(), isClean());
        startTime_ = null;
      }
      return startTimeBuilder_;
    }
<pre>
Output only. Time when the request was received.
</pre>

<code>.google.protobuf.Timestamp start_time = 3;</code>
java-video-intelligence/proto-google-cloud-video-intelligence-v1p1beta1/src/main/java/com/google/cloud/videointelligence/v1p1beta1/VideoAnnotationProgress.java