An object that contains a set of related objects. An object's position in the collection can change whenever a change occurs in the collection; therefore, the position of any specific object in the collection can vary. The Collection object is the standard example of a collection class; instances of the class are collections. Collections must implement a method called NewEnum that accepts no arguments, returns an appropriate IUnknown object, and has its VB_UserMemId attribute set to -4.
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