Question.fromJson constructor
Implementation
factory Question.fromJson(Map<String, dynamic> json) => Question(
questionIdentifier: json['question_identifier'] as String,
questionText: json['question_text'] as String,
questionType: json['question_type'] as String,
userAnswer: json['user_answer'] != null
? UserAnswer.fromJson((json['user_answer'] as Map).cast<String, dynamic>())
: null,
);