Captured from a real `junit-platform-console-standalone --details=tree` run against
CsvFileSourceTest, compiled and executed for real against the committed
src/test/resources/test-data/postcode-regions.csv fixture.

╷
├─ JUnit Platform Suite ✔
├─ JUnit Jupiter ✔
│  └─ CsvFileSourceTest ✔
│     └─ shouldMapPostcodeToRegion(String, String) ✔
│        ├─ postcode "SW1A" should map to region "London" ✔
│        ├─ postcode "M1" should map to region "Manchester" ✔
│        ├─ postcode "EH1" should map to region "Edinburgh" ✔
│        ├─ postcode "CF10" should map to region "Cardiff" ✔
│        └─ postcode "BT1" should map to region "Belfast" ✔
└─ JUnit Vintage ✔

Test run finished after 208 ms
[         5 tests successful      ]
[         0 tests failed          ]

@CsvFileSource reads real rows from a real file on the classpath instead of inline strings --
the five rows above are read from the CSV fixture's header row (postcode,region) plus five data
rows, which exactly match the five entries Geocoder.java hardcodes internally.