public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
EditorGUI.BeginProperty(position, label, property);
SerializedProperty assetProp = property.FindPropertyRelative("_asset");
EditorGUI.BeginChangeCheck();
EditorGUI.ObjectField(position, assetProp, label);
if (EditorGUI.EndChangeCheck())
{
AnimationTextureRef animationTexture = SerializedPropertyUtils.GetSerializedPropertyValue <AnimationTextureRef>(property);
animationTexture.UnloadTexture();
}
EditorGUI.EndProperty();
}