System.Dynamic.DynamicMetaObjectBinder.GetUpdateExpression C# (CSharp) Method

        public Expression GetUpdateExpression(Type type)
        {
            return Expression.Goto(CallSiteBinder.UpdateLabel, type);
        }

            /// <summary>
            /// Adds a dynamic test which checks if the version has changed.  The test is only necessary for
            /// performance as the methods will do the correct thing if called with an incorrect version.
            /// </summary>
            private DynamicMetaObject AddDynamicTestAndDefer(DynamicMetaObjectBinder binder, ExpandoClass klass, ExpandoClass originalClass, DynamicMetaObject succeeds)
            {
                Expression ifTestSucceeds = succeeds.Expression;

                if (originalClass != null)
                {
                    // we are accessing a member which has not yet been defined on this class.
                    // We force a class promotion after the type check.  If the class changes the
                    // promotion will fail and the set/delete will do a full lookup using the new
                    // class to discover the name.
                    Debug.Assert(originalClass != klass);

                    ifTestSucceeds = Expression.Block(
                        Expression.Call(
                            null,
                            typeof(RuntimeOps).GetMethod("ExpandoPromoteClass"),
                            GetLimitedSelf(),
                            Expression.Constant(originalClass, typeof(object)),
                            Expression.Constant(klass, typeof(object))
                            ),
                        succeeds.Expression
                        );
                }

                return(new DynamicMetaObject(
                           Expression.Condition(
                               Expression.Call(
                                   null,
                                   typeof(RuntimeOps).GetMethod("ExpandoCheckVersion"),
                                   GetLimitedSelf(),
                                   Expression.Constant(originalClass ?? klass, typeof(object))
                                   ),
                               ifTestSucceeds,
                               binder.GetUpdateExpression(ifTestSucceeds.Type)
                               ),
                           GetRestrictions().Merge(succeeds.Restrictions)
                           ));
            }