copyWith method
Creates a copy of this object with the given fields replaced with the new values.
For nullable fields, passing null leaves the field unchanged (standard
Dart copyWith behavior). To explicitly reset a nullable field to
null, pass a domain-invalid sentinel value:
String?fields: pass an empty string (isEmpty) to reset tonull.List?/Set?fields: pass an empty collection (isEmpty) to reset tonull.double?/int?fields (positive-only, e.g. height/width/angle): pass a negative value (isNegative) to reset tonull.
These sentinel values are never valid for the respective fields (enforced by constructor assertions), making the intent unambiguous.
Implementation
CapitalInfo copyWith({Capital? capital, LatLng? latLng}) => CapitalInfo(
capital: capital ?? this.capital,
latLng: latLng ?? this.latLng,
);