build method
Generates the complete Dart code for the model class
Implementation
String build() {
final sb = StringBuffer();
// 1. Imports (if needed, e.g., for nested models in separate files)
_buildImports(sb);
// 2. Class Definition
sb.writeln('class $modelName {');
// 3. Fields
_buildFields(sb);
sb.writeln();
// 4. Constructor
_buildConstructor(sb);
sb.writeln();
// 5. fromJson factory
_buildFromJson(sb);
sb.writeln();
// 6. toJson method
_buildToJson(sb);
sb.writeln('}');
return sb.toString();
}