/// <summary>Registers a collection of <see cref="Currency"/> objects.
            /// </summary>
            /// <param name="values">The collection of <see cref="Currency"/> objects to register.</param>
            /// <returns>For each element of <paramref name="values"/> a value indicating whether the <see cref="Currency"/>
            /// object has been inserted.</returns>
            public ItemAddedState[] Add(params Currency[] values)
            {
                if (values == null)
                {
                    return(null);
                }
                var stateList = new List <ItemAddedState>();

                for (int j = 0; j < values.Length; j++)
                {
                    stateList.Add(CommonCurrency.Add(values[j]));
                }
                return(stateList.ToArray());
            }
 /// <summary>Registers a specific <see cref="Currency"/> object.
 /// </summary>
 /// <param name="value">The <see cref="Currency"/> object to register.</param>
 /// <returns>A value indicating whether <paramref name="value"/> has been inserted.</returns>
 public ItemAddedState Add(Currency value)
 {
     return(CommonCurrency.Add(value));
 }