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.