/// <summary>
        /// Add filter for value type.
        /// </summary>
        /// <typeparam name="TModel">Model type.</typeparam>
        /// <typeparam name="TProperty">Type target property.</typeparam>
        /// <param name="key">Filter key</param>
        /// <param name="filter">Value type filter.</param>
        /// <returns>Value type filter configuration.</returns>
        public IValueTypeFilterConfiguration <TModel, TProperty> Add <TModel, TProperty>(string key, IValueTypeFilter <TModel, TProperty> filter) where TProperty : struct, IComparable, IComparable <TProperty>, IEquatable <TProperty>
        {
            var configuration = new ValueTypeFilterConfiguration <TModel, TProperty>(filter);

            _filters[key] = filter;

            return(configuration);
        }
 internal ValueTypeFilterConfiguration(IValueTypeFilter <TModel, TProperty> filter)
 {
     _filter = filter;
 }