Highway Sensor Journey Count

Karat practical coding task with highway sensor logs: debug an existing test, then count completed entry-to-exit journeys by vehicle. Requirements The domain has highway entrances, exits, and intermediate checkpoints. Each location has a sensor that records when a car passes. Input logs are sorted by time and include timestamp, sensor, and car identifier. Part 1: inspect given code and tests, then debug why a test is failing. Part 2: write a function that counts how many journeys appear in a log segment. A journey is completed when the same car goes from an entry sensor to an exit sensor. Notes Track per-car state rather than only aggregate counts. Clarify how to treat duplicate entries, missing exits, exits without prior entries, and checkpoint-only observations.