Reduce duplicate detections when using async streaming

[manuGil]

The EPE detects multiple event for the same observation when using concurrent futures to stream data from each Datastream.

Good to know:

• The number of event that is ducplicated is not consistent between runs.
• Adding a delay between each post reduces the number of duplicates.
• The SiddhiQL approach to reduce duplication is to filter events in the SiddhiApp using a unit identifier for each observation.

[manuGil]

There is ambiguity in the queries with multiple data streams. Either the SiddhiQL query is wrong or stream generator is not sending data for both stream.

Yes, the stream generator seems to only send data for the NO2 when multiple events are given.