When the user wants to measure or improve the *quality* of their existing test suite via mutation testing. Use when the user mentions "mutation testing," "mutation score," "Stryker," "PIT," "PITest," "mutmut," "go-mutesting," "Mutmut," "mutator," "killed mutant," "surviving mutant," "mutation coverage," or "is our coverage strong." For line coverage see code-coverage. For overall strategy see test-strategy.
