public Builder addProperties(
        int index, com.google.cloud.vision.v1p3beta1.Property.Builder builderForValue) {
      if (propertiesBuilder_ == null) {
        ensurePropertiesIsMutable();
        properties_.add(index, builderForValue.build());
        onChanged();
      } else {
        propertiesBuilder_.addMessage(index, builderForValue.build());
      }
      return this;
    }
<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.v1p3beta1.Property properties = 9;</code>
java-vision/proto-google-cloud-vision-v1p3beta1/src/main/java/com/google/cloud/vision/v1p3beta1/EntityAnnotation.java