class CaseStudyPlan { final String planId; final String planTitle; final String planTeacher; final String thumbnail; CaseStudyPlan({ required this.planId, required this.planTitle, required this.planTeacher, required this.thumbnail, }); factory CaseStudyPlan.fromJson(Map json) { return CaseStudyPlan( planId: json['casestudy lesson id'] ?? '아이디 없음', planTitle: json['course_name'] ?? '제목 없음', planTeacher: json['course_description'] ?? '', thumbnail: json['course_thumbnail'] ?? '', ); } }