removePolylines method
Removes the specified lines
from the map. The lines must be current
members of the lines
set.
Change listeners are notified once the lines have been removed on the platform side.
The returned Future completes once listeners have been notified.
Implementation
Future<void> removePolylines(Iterable<Line> lines) async {
await polylineManager!.removeAll(lines);
notifyListeners();
}