What to do when there is multiple “main” peaks in find_peak

In find_peak, we start by finding the min/max value (line 105--110) and then look for all peaks the value of which is “close-enough” to that peak.

What should we do when the min/max value is not unique? Is taking the first max/min value enough?

There is a test in lines 116-117 that can be remove if we are sure that this is ok. The examples in example_egg trigger the warning.