  Coincidental correctness (CC) arises when a defective program produces the
correct output despite the fact that the defect within was exercised.
Researchers have recognized the negative impact of coincidental correctness,
and the authors have previously conducted a study demonstrating its prevalence
in test suites. However, that study was limited to system tests and small
subjects seeded with artificial defects. In this paper, we conduct a wider
scope study of CC that addresses the following research questions in the
context of the Defects4J benchmark:
  RQ1: Is CC prevalent in Defects4J?
  RQ2: Is CC affected by the testing levels in Defects4J?
  RQ3: Do CC tests induce peculiar infection paths in Defects4J?
  RQ4: Are the infections likely to be nullified within or outside the buggy
method? ....
