Random coverage

Coverage reports for some PRs report decrease in overall coverage, sometimes even when PR does not touch code at all. The following list links to the parts of code that are only sometimes tested. The problem can be fixed by writing a test that always test the linked code.

Widgets

• https://codecov.io/gh/biolab/orange3/compare/1a4652ab07fb1d4e4246f87c7f716d4783abea92...959a79e14344856da534d7dc1bc0b4f1f92aaaa4/src/Orange/widgets/evaluate/owtestlearners.py [ solved results_add_by_model in PR #2567 ]
• https://codecov.io/gh/biolab/orange3/compare/1a4652ab07fb1d4e4246f87c7f716d4783abea92...1278e52be21ab21173f6d5e3d8199f2e05c6c660/src/Orange/widgets/evaluate/owconfusionmatrix.py
• https://codecov.io/gh/biolab/orange3/compare/1a4652ab07fb1d4e4246f87c7f716d4783abea92...959a79e14344856da534d7dc1bc0b4f1f92aaaa4/src/Orange/widgets/visualize/owmap.py
• https://codecov.io/gh/biolab/orange3/compare/1a4652ab07fb1d4e4246f87c7f716d4783abea92...959a79e14344856da534d7dc1bc0b4f1f92aaaa4/src/Orange/widgets/gui.py

Setting Migrations

• https://codecov.io/gh/biolab/orange3/compare/1a4652ab07fb1d4e4246f87c7f716d4783abea92...959a79e14344856da534d7dc1bc0b4f1f92aaaa4/src/Orange/widgets/data/owrank.py
• https://codecov.io/gh/biolab/orange3/compare/1a4652ab07fb1d4e4246f87c7f716d4783abea92...959a79e14344856da534d7dc1bc0b4f1f92aaaa4/src/Orange/widgets/unsupervised/owpca.py
• https://codecov.io/gh/biolab/orange3/compare/1a4652ab07fb1d4e4246f87c7f716d4783abea92...959a79e14344856da534d7dc1bc0b4f1f92aaaa4/src/Orange/widgets/visualize/owlinearprojection.py