// Concat
        public static IComponentBrokerRepository Concat(this IComponentBrokerRepository first, IComponentBrokerRepository second)
        {
            #region Contracts

            if (first == null) throw new ArgumentNullException();
            if (second == null) throw new ArgumentNullException();

            #endregion

            // Return
            return new ConcatComponentBrokerRepository(first, second);
        }
        // Constructors
        public ConcatComponentBrokerRepository(IComponentBrokerRepository first, IComponentBrokerRepository second)
        {
            #region Contracts

            if (first == null) throw new ArgumentNullException();
            if (second == null) throw new ArgumentNullException();

            #endregion

            // Arguments
            _first = first;
            _second = second;
        }