anchor.diff:      label = m["label"];
       value = m["value"];
     }
  +
  +  static Map _toMap(Item i) =>  {"label": i.label, "value": i.value};
  +
   }
  
positive.code:     phones = (m["phones"] as Iterable<Map>)?.map((m) => new Item.fromMap(m));
      postalAddresses = (m["postalAddresses"] as Iterable<Map>)?.map((m) => new PostalAddress.fromMap(m));
    }
  }
  
  class PostalAddress{
  
negative.code:     return contacts.map((m) => new Contact.fromMap(m));
    }
  
    /**
     * Adds the [contact] to the device contact list
     */
    static Future addContact(Contact contact) => _channel.invokeMethod('addContact', Contact._toMap(contact));
  }
  
  class Contact{
  