Route constraint reference for the param type - list of long

Question

I am writing an GET method on my ASP.NET core controller which takes a list of longs as an parameter.

[HttpGet("RetrieveAccessorNamesForAccessorIds/{accessorIds}")]
public async Task<IActionResult> RetrieveAccessorNamesForAccessorIds(List<long> accessorIds)

I need to write a route constraint reference so autorest can find the param type when trying to generate packages based off the swagger definition. In the code above, Autorest throws an error as it is unaware of what type to use for the param accessorIds.

The issue is I cannot find what route constraint for this scenario as lists are not an option in the documentation.