toJson method
Implementation
Map<String, dynamic> toJson() {
Map<String, dynamic> dict = {};
dict['membership_type'] = membershipType;
if (userId != null) dict['user_id'] = userId;
if (name != null) dict['name'] = name;
if (phone != null) dict['phone'] = phone;
if (email != null) dict['email'] = email;
return dict;
}