mitgliederverwaltung/test/fixtures/csv_with_unknown_custom_field.csv

1	first_name	last_name	email	street	postal_code	city	UnknownCustomField
2	Alice	Smith	alice.smith@example.com	Main Street 1	12345	Berlin	SomeValue
3	Bob	Johnson	bob.johnson@example.com	Park Avenue 2	54321	Munich	AnotherValue