Update Events not possible

[Frank-Vito]

This issue is for a: (mark with an x)

- [ x] bug report -> please search issues before submitting
- [ x] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

Minimal steps to reproduce

When sending multiple events with and identical timestamp and id this results in multiple events being created.

Expected/desired behavior

If an event with the same timestamp and id already exists, the values should be updated /overwritten.

Mention any other details that might be useful

consider the following scenario.
Where are using TSI to store forecast for the next 14 days. These forecasts are updated every day , creating a sliding window of updated forecasts.
Idea is to have a single TSI instance containing the latest forecast. Because the events are not updated, but added the values returned by TSI are incorrect.