public com.google.cloud.vision.v1p1beta1.Property.Builder addPropertiesBuilder(int index) {
      return getPropertiesFieldBuilder()
          .addBuilder(index, com.google.cloud.vision.v1p1beta1.Property.getDefaultInstance());
    }
<pre>
Some entities may have optional user-supplied `Property` (name/value)
fields, such a score or string that qualifies the entity.
</pre>

<code>repeated .google.cloud.vision.v1p1beta1.Property properties = 9;</code>
java-vision/proto-google-cloud-vision-v1p1beta1/src/main/java/com/google/cloud/vision/v1p1beta1/EntityAnnotation.java