toMap method
Implementation
Map<String, dynamic> toMap() => {
'@type': 'ContactPoint',
'telephone': telephone,
'contactType': contactType,
if (areaServed != null) 'areaServed': areaServed,
if (availableLanguage != null) 'availableLanguage': availableLanguage,
if (email != null) 'email': email,
};