init method
Implementation
Future<void> init(int mapId) async {
MethodChannel channel;
if (!_channels.containsKey(mapId)) {
channel = MethodChannel('${Channel.channel}_$mapId');
channel.setMethodCallHandler(
(MethodCall call) => _handleMethodCall(call, mapId));
_channels[mapId] = channel;
return channel.invokeMethod<void>(Method.MapWaitForMap);
}
}