toJson method
JSON으로 변환
Implementation
Map<String, dynamic> toJson() => {
'id': id,
'provider': provider,
if (name != null) 'name': name,
if (email != null) 'email': email,
if (image != null) 'image': image,
if (phone != null) 'phone': phone,
if (birthday != null) 'birthday': birthday,
if (birthyear != null) 'birthyear': birthyear,
if (gender != null) 'gender': gender,
if (ageRange != null) 'ageRange': ageRange,
if (ci != null) 'ci': ci,
};