I'd suggest taking a look at the documentation, Splunk usually offers examples at the bottom of their docs pages https://docs.splunk.com/Documentation/Splunk/8.0.0/SearchReference/Makeresults#Examples. The command doesn't actually create any "events", it looks like. It just creates "statistics" to play around with. For example, if you wanted to alert on something like "what happens when a field has a value of X", you could play around with the syntax like this:
In this example, I create 3 fake rows, use streamstats to effectively number them, add a field with an eval/case pairing. You can then set this up as an alert and ensure that it successfully triggers, sends the right message to the right location, etc. You can probably extrapolate this to whatever case you need!