com.unity.perception/com.unity.perception/Editor/Randomization/VisualElements/Randomizer/RandomizerReorderingIndicator.cs

using UnityEngine.UIElements;

namespace UnityEngine.Experimental.Perception.Randomization.Editor
{
    class RandomizerReorderingIndicator : VisualElement
    {
        public RandomizerReorderingIndicator()
        {
            AddToClassList("randomizer__reordering-hover-indicator");
        }
    }
}