private com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.visionai.v1.StreamAnnotation,
                com.google.cloud.visionai.v1.StreamAnnotation.Builder,
                com.google.cloud.visionai.v1.StreamAnnotationOrBuilder>
            getAnnotationFieldBuilder() {
          if (annotationBuilder_ == null) {
            annotationBuilder_ =
                new com.google.protobuf.SingleFieldBuilderV3<
                    com.google.cloud.visionai.v1.StreamAnnotation,
                    com.google.cloud.visionai.v1.StreamAnnotation.Builder,
                    com.google.cloud.visionai.v1.StreamAnnotationOrBuilder>(
                    getAnnotation(), getParentForChildren(), isClean());
            annotation_ = null;
          }
          return annotationBuilder_;
        }
<pre>
Active zone annotation from the user.
</pre>

<code>.google.cloud.visionai.v1.StreamAnnotation annotation = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/OccupancyCountingPredictionResult.java