addWayholders method
Implementation
void addWayholders(List<Wayholder> wayholders) {
wayholders.forEach((test) {
assert(test.openOutersRead.isNotEmpty || test.closedOutersRead.isNotEmpty);
});
assert(content == null);
this.wayholders.addAll(wayholders);
wayCount += wayholders.length;
//count += wayholders.fold(0, (combine, test) => combine + test.openOuters.length + test.closedOuters.length);
}