@java.lang.Override
  public int hashCode() {
    if (memoizedHashCode != 0) {
      return memoizedHashCode;
    }
    int hash = 41;
    hash = (19 * hash) + getDescriptor().hashCode();
    hash = (37 * hash) + CATEGORY_MASK_FIELD_NUMBER;
    hash = (53 * hash) + getCategoryMask().hashCode();
    hash = (37 * hash) + CONFIDENCE_MASK_FIELD_NUMBER;
    hash = (53 * hash) + getConfidenceMask().hashCode();
    hash = (29 * hash) + getUnknownFields().hashCode();
    memoizedHashCode = hash;
    return hash;
  }
<pre>
A one channel image which is encoded as an 8bit lossless PNG. The size of
the image will be the same as the original image. For a specific pixel,
darker color means less confidence in correctness of the cateogry in the
categoryMask for the corresponding pixel. Black means no confidence and
white means complete confidence.
</pre>

<code>string confidence_mask = 2;</code>

@return The bytes for confidenceMask.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/ImageSegmentationPredictionResult.java