Fetching the events from an OPC UA Server|OPC UA Standard|Forum|OPC Foundation

Hi Team,

Our OPC UA client uses OPCUA legacy Java stack. The client retrieves the information model from the OPC UA server and then browses over it for listing the events to render on the UI. The following steps are being taken for this browsing process. 
1. Check the selected node, if it subscribes to events add it to the list of events else find its children.
2. Iterate over the children. If the child is subtype of Identifiers.GeneratesEvent recursively call this function.
3. else go to the list of parents and find parents which are subtype of Identifiers.HasSubtype.
4. Iterate over these parents and recursively call this function.

While doing this below events are missed/filtered out and hence not rendered on the UI
1. SystemEventType
2. EventQueueOverflowEventType
3. TransitionEventType
4. SampleEventType
5. TraceEventType

Please assist to efficiently browse the information model so that all events can be listed and rendered for further mapping and deployment.

Thanks,

Chirantan