When the same die position appears more than once in the input, buildWaferMap resolves it using a retest policy. last (default) keeps the final result; first keeps the initial probe; best keeps the pass result when one exists (using passBins), falling back to the lowest hbin as a tiebreaker among failures; worst prefers a fail result, falling back to the highest hbin. Dies with multiple probes get a retestCount — click any die to see its details. A tester can also say outright that a record replaces an earlier one (STDF PART_FLG): switch on supersedes to flag every retest that made its die worse with supersedes: 'position'. Under best or first those dies now keep the flagged retest, because a flagged record wins whatever the policy says.