add 2x2 test

[malmans2]

• Closes Add a test to make sure Zco output does not change with x and y #23
• Passes pre-commit run --all-files
• Project, label, and assignee tabs are populated

[codecov]

Codecov Report

Merging #28 (fa031b6) into main (34ca3ca) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #28   +/-   ##
=======================================
  Coverage   93.12%   93.12%           
=======================================
  Files           4        4           
  Lines         160      160           
=======================================
  Hits          149      149           
  Misses         11       11           

Flag	Coverage Δ
unittests	93.12% <ø> (ø)

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[malmans2]

Same thing, but I think it makes more sense to load it locally.
This is a module that we only use for testing.

Everything else, makes sense to import from the installed package.