Interacts with a key/value store shared by one or more clients connected to a Concert session. The store is like a TMap. The implementation requires the 'Blob' to be defined as a USTRUCT() structure, which provides the serialization mechanism. The system automatically wraps primitive types like integers, floating, bool and strings into USTRUCT() for you. If you need to store container types like TArray<>, TMap<> or TSet<> or custom types, you will need to put them into a USTRUCT() struct similare to the example below showing how to use custom types.