public int getSupportedAnnotationTypesCount() {
      return supportedAnnotationTypes_.size();
    }
<code>
repeated .google.cloud.visionai.v1.StreamAnnotationType supported_annotation_types = 15 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>

@return The count of supportedAnnotationTypes.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/Processor.java