build method
Implementation
CustomerAttributes build() {
return CustomerAttributes._(
displayName: _displayName,
firstName: _firstName,
lastName: _lastName,
email: _email,
gender: _gender,
mobile: _mobile,
dateOfBirth: _dateOfBirth,
joinDate: _joinDate,
preferredLanguage: _preferredLanguage,
customAttributes: _customAttributes,
additionalAttributes: _additionalAttributes,
);
}