Small fixes

src/main/java/nl/tudelft/tam/io/ImportHandler.java

@@ -131,6 +131,14 @@ public abstract class ImportHandler<E> {
 		}
 	}
 
+	protected Optional<Boolean> parseBoolean(String value) {
+		if (Set.of("1", "true", "yes", "y").contains(value.toLowerCase()))
+			return Optional.of(true);
+		if (Set.of("0", "false", "no", "n").contains(value.toLowerCase()))
+			return Optional.of(false);
+		return Optional.empty();
+	}
+
 	protected Optional<LocalDate> parseDate(String date) {
 		try {
 			return Optional.of(LocalDate.parse(date, DateTimeFormatter.ofPattern("dd-MM-yyyy")));