serialize method Null safety

  1. @override
Map<String, String> serialize()
override

This method is meant to be overridden if data in addition to finder is serialized to JSON.

Example:

Map<String, String> toJson() => super.toJson()..addAll({
  'foo': this.foo,
});

Implementation

@override
Map<String, String> serialize() => super.serialize()..addAll(<String, String>{
  'dx': '$dx',
  'dy': '$dy',
  'duration': '${duration.inMicroseconds}',
  'frequency': '$frequency',
});