Can I read the CORS settings in .NET 5 after configuring them in IServiceCollection?

Question

I configure my CORS settings according to the example here: https://stackoverflow.com/a/65039768/10069673

    public void ConfigureServices(IServiceCollection services)
    {
        // ...

        services.AddCors(options =>
        {
            options.AddPolicy(name: "AllowedCorsOrigins",
                builder =>
                {
                    builder
                        .SetIsOriginAllowed(IsOriginAllowed)
                        .AllowAnyHeader()
                        .AllowAnyMethod()
                        .AllowCredentials();
                });
        });
        // ...

I would like to write a unit test to verify that CORS is configured correctly. IsOriginAllowed is a private function, therefore I can't call it directly in a unit test.

Can I use the IServiceCollection object or a mock of the interface to check if a URI is allowed/blocked by the previously configured CORS settings?