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📜 WAYPOINT LESSON

Checkpoint: Functional & Collectors

⭐⭐ intermediate⏳ 15 min read📍 Lesson 81 of 180

Graded checkpoint: analytics reducers over an event log using groupingBy, toMap merges, and partitioning.

Checkpoint — functional Java

You can now: reshape collections in a single pass with downstream collectors, merge duplicate keys safely, and judge when a loop beats a pipeline. Prove it with an analytics reducer.