How to retrieve list of all implemented versions of my api?

I'm using aspnet-api-versioning in my WebApi project and it works fine. Versions are not hardcoded, they are retrieved from the namespaces.

Now I would like to retrieve the list of already implemented versions. I want to create some endpoint (let's call it GetApiVersions) that user could call to retrieve a simple collection of existing api version numbers, e.g. [1, 2, 3].

In the code responsible for selecting a correct api version based on the retrieved request (CurrentImplementationApiVersionSelector, SelectVersion method), there is an ApiVersionModel parameter with the ImplementedApiVersions property.

The ImplementedApiVersions property seems to be exactly what I need, but I have no idea how to access it within my GetApiVersions endpoint. Is there a way to retrieve it? Or is there any other way to programmatically retrieve a list of implemented api versions?

I wasn't able to access ImplementedApiVersions property. I had to come up with a workaround. I've created a service (called ApiVersionService) with a static field (List<string> ApiVersions). Service allows to register and read registered versions. As I'm using swagger, I registered all versions in SwaggerConfig.cs file:

configuration.EnableSwagger(ApiDocConfiguration.RouteTemplate, swagger =>
{
    swagger.MultipleApiVersions(
        (apiDescription, version) => apiDescription.GetGroupName() == version,
        info =>
        {
            foreach (var group in apiExplorer.ApiDescriptions)
            {
                apiVersionService.AddApiVersion(group.Name);
                // some other code
            }
        });
});

Simple endpoint allows me to retrieve all versions:

    [HttpGet]
    [Route("versions")]
    public IHttpActionResult GetVersions()
    {
        // apiVersionService returns the data stored in ApiVersions field
        var versions = apiVersionService.GetApiVersions();
        return Ok(versions);
    }