This class extends Vector to manage a list of Property objects that represent state variable changes in UPnP event notifications. It provides a typed container for properties that are included in event messages sent to subscribers.

Key features:

• Type-safe property collection management
• XML element name definition for serialization
• Vector-based implementation for efficient access
• Property retrieval by index

This class is used in UPnP event notifications to group multiple property changes that occur simultaneously, allowing subscribers to receive batched updates about service state variable changes.