System.Linq.Expressions.BinaryExpression.ReduceMember C# (CSharp) Метод

        private Expression ReduceMember()
        {
            MemberExpression member = (MemberExpression)Left;

            if (member.Expression == null)
            {
                // static member, reduce the same as variable
                return ReduceVariable();
            }
            else
            {
                // left.b (op)= r
                // ... is reduced into ...
                // temp1 = left
                // temp2 = temp1.b (op) r
                // temp1.b = temp2
                // temp2
                ParameterExpression temp1 = Variable(member.Expression.Type, "temp1");

                // 1. temp1 = left
                Expression e1 = Expression.Assign(temp1, member.Expression);

                // 2. temp2 = temp1.b (op) r
                ExpressionType op = GetBinaryOpFromAssignmentOp(NodeType);
                Expression e2 = Expression.MakeBinary(op, Expression.MakeMemberAccess(temp1, member.Member), Right, false, Method);
                LambdaExpression conversion = GetConversion();
                if (conversion != null)
                {
                    e2 = Expression.Invoke(conversion, e2);
                }
                ParameterExpression temp2 = Variable(e2.Type, "temp2");
                e2 = Expression.Assign(temp2, e2);

                // 3. temp1.b = temp2
                Expression e3 = Expression.Assign(Expression.MakeMemberAccess(temp1, member.Member), temp2);

                // 3. temp2
                Expression e4 = temp2;

                return Expression.Block(
                    new TrueReadOnlyCollection<ParameterExpression>(temp1, temp2),
                    new TrueReadOnlyCollection<Expression>(e1, e2, e3, e4)
                );
            }
        }