IHttpContextAccessor being singleton or not

[jiimaho]

Today IHttpContextAccessor is registered as singleton. I think it would be better to throw a runtime error if this is not the case, then the consumer would have to wire up this dependency manually instead. What do you think?

    public static IServiceCollection AddSwaggerGenWithBearerToken(this IServiceCollection services, Action<SwaggerGenOptions> setupAction)
    {
        services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();
        services.AddSwaggerGen(options =>
        {
            setupAction.Invoke(options);
            options.EnableBearerTokenAuthorization();
        });
        return services;
    }