The file has 35 rows in its province column. One of them is the country. It is not flagged, not last, and not named differently from the rest — in ump.csv it is simply another row.

the province column
rows in the file	35
actual provinces	34
the aggregate	INDONESIA

why it matters more than it sounds A national figure is not an extreme, so it does not announce itself as an outlier. It sits near the middle and quietly pulls every measure of spread inward, makes every correlation look a little tidier, and adds one fake province to every count. The pipeline asserts the row is present and removes it by name; if a future version of the file drops it, the build fails rather than silently changing every number.