protected override object GetInstance(Type serviceType, string key)
        {
            string contract = string.IsNullOrEmpty(key) ? AttributedModelServices.GetContractName(serviceType) : key;
            var    exports  = _container.GetExportedValues <object>(contract);

            if (exports.Any())
            {
                return(exports.First());
            }

            throw new Exception($"Could not locate any instances of contract {contract}.");
        }
 protected override IEnumerable <object> GetAllInstances(Type serviceType)
 {
     return(_container.GetExportedValues <object>(AttributedModelServices.GetContractName(serviceType)));
 }