anchor.diff:  }
   
   class Contact {
  -  Contact(
  -      {this.givenName,
  -      this.middleName,
  -      this.prefix,
  -      this.suffix,
  -      this.familyName,
  -      this.company,
  -      this.jobTitle,
  -      this.emails,
  -      this.phones,
  -      this.postalAddresses,
  -      this.avatar});
  +  Contact({
  +    this.givenName,
  +    this.middleName,
  +    this.prefix,
  +    this.suffix,
  +    this.familyName,
  +    this.company,
  +    this.jobTitle,
  +    this.emails,
  +    this.phones,
  +    this.postalAddresses,
  +    this.avatar,
  +  });
   
  -  String identifier,
  -      displayName,
  -      givenName,
  -      middleName,
  -      prefix,
  -      suffix,
  -      familyName,
  -      company,
  -      jobTitle;
  +  String identifier, displayName, givenName, middleName, prefix, suffix, familyName, company, jobTitle;
     Iterable<Item> emails = [];
     Iterable<Item> phones = [];
     Iterable<PostalAddress> postalAddresses = [];
  
positive.code: }
  
  class PostalAddress {
    PostalAddress(
        {this.label,
        this.street,
        this.city,
        this.postcode,
        this.region,
        this.country});
    String label, street, city, postcode, region, country;
  
    PostalAddress.fromMap(Map m) {
  
negative.code:   }
  
    static Map _toMap(PostalAddress address) => {
      "label": address.label,
      "street": address.street,
      "city": address.city,
      "postcode": address.postcode,
      "region": address.region,
      "country": address.country
    };
  }
  
  /// Item class used for contact fields which only have a [label] and
  