docs: public BuildableType.Builder clear() {
      BuildableType_Builder defaults = new BuildableType.Builder();
      type = defaults.type;
      builderType = defaults.builderType;
      mergeBuilder = defaults.mergeBuilder;
      partialToBuilder = defaults.partialToBuilder;
      builderFactory = defaults.builderFactory;
      suppressUnchecked = defaults.suppressUnchecked;
      _unsetProperties.clear();
      _unsetProperties.addAll(defaults._unsetProperties);
      return (BuildableType.Builder) this;
    }