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Checkpoint: Generics & PECS

intermediate15 min readLesson 74 of 180

Graded checkpoint: a bounded topN, a wildcard sum, and a drain that exercises both wildcard directions.

Checkpoint — generics

You can now: bound type parameters so methods actually work, choose wildcards by the PECS rule, and route around erasure with Class tokens. Prove it with a reusable collector API.