Unity 2020.1 version does not include [NonReorderable] Attribute

[OU2018]

What is the current behavior? Library\PackageCache\dev.yarnspinner.unity@ac33e9168b\Editor\Importers\YarnProjectImporter.cs(137,10): error CS0246: The type or namespace name 'NonReorderableAttribute' could not be found (are you missing a using directive or an assembly reference?) Library\PackageCache\dev.yarnspinner.unity@ac33e9168b\Editor\Importers\YarnProjectImporter.cs(137,10): error CS0246: The type or namespace name 'NonReorderable' could not be found (are you missing a using directive or an assembly reference?)

Please provide the steps to reproduce, and if possible a minimal demo of the problem: Using Unity 2020.1.14f1 version, import the YarnSpinner plugin from git.

What is the expected behavior? no error.

Please tell us about your environment:

• Yarn Spinner Version: 2.2.1
• Unity Version:Unity 2020.1.14f1 Personal

Other information

I found a way to fix this problem. It is to change UNITY_2020_1 in the wrong place to UNITY_2020_2. Because there is no [NonReorderable] in the 2020.1 version of the manual, it will be available in 2020.2.