How to mock IEnumerable

This question already has an answer here:

• How to mock an IFormFile for a unit/integration test in ASP.NET Core 1 MVC 6? 2 answers
• xunit test for IFormFile field in Asp.net Core 2 answers

I'm creating WebApi in .NetCore 2.2. I have an action POST where one parameter is IEnumerable<IFromFile>

public IActionResult Create([ModelBinder(BinderType = typeof(JsonModelBinder))] OfferPlaceDto offerPlaceDto,
        IEnumerable<IFormFile> formFiles)

I have to write xUnit test of this action, but I do not know how mock this formFiles.

Someone would have an idea?