System.Linq.Expressions.Error.MustReduceToDifferent C# (CSharp) Метод

        internal static Exception MustReduceToDifferent()
        {
            return new ArgumentException(Strings.MustReduceToDifferent);
        }
        /// <summary>

        /// <summary>
        /// Reduces this node to a simpler expression. If CanReduce returns
        /// true, this should return a valid expression. This method is
        /// allowed to return another node which itself must be reduced.
        /// </summary>
        /// <returns>The reduced expression.</returns>
        /// <remarks >
        /// Unlike Reduce, this method checks that the reduced node satisfies
        /// certain invariants.
        /// </remarks>
        public Expression ReduceAndCheck()
        {
            if (!CanReduce)
            {
                throw Error.MustBeReducible();
            }

            Expression newNode = Reduce();

            // 1. Reduction must return a new, non-null node
            // 2. Reduction must return a new node whose result type can be assigned to the type of the original node
            if (newNode == null || newNode == this)
            {
                throw Error.MustReduceToDifferent();
            }
            if (!TypeUtils.AreReferenceAssignable(Type, newNode.Type))
            {
                throw Error.ReducedNotCompatible();
            }
            return(newNode);
        }