When this property value is set, all events not fired as the result of an asynchronous operation will have the associated event handlers called back on the thread that created the specific .
Assembly: System.Net (in System.Net.dll)
[<BrowsableAttribute(false)>] member SynchronizingObject : ISynchronizeInvoke with get, set
The default set value for this property is a null reference (Nothing in Visual Basic), indicating that all event handlers are called on a system thread pool thread.
This property is typically set to a UI element such as a Form instance.