CountryData constructor
Creates a CountryData instance.
API users do not typically construct this object directly.
Parameters
name: (String) Human-readable country name.isoCode: (String) ISO 3166-1 alpha-3 country code (e.g.USA).flagImage: (Img?) Optional flag image object; null when not present.
Implementation
CountryData({required this.name, required this.isoCode, this.flagImage});