Unexpected mutation of Comparer when added to ComparerCollection (maybe?)

[ryan-kipawa]

I have two comparers

# compares model version A to observation X
cmp_a
# compares model version B to observation X
cmp_b

When I do this:

ms.ComparerCollection([cmp_a, cmp_b]).skill()

Followed by this:

cmp_a.skill()

I realized that cmp_a now also has the model results from cmp_b. Is this working as intended? I can try to produce a minimal reproduceable example soon..

Edit: if I make copies of the comparers passed to the collection, then there's no mutation.

[ecomodeller]

I will fix it in #521 which is closely related to this.