anchor.diff:        .lens((template) => template.isRelatedTo.isRelatedTo = subject);
   
     _prettyPrint(subject);
  +
  +  /*
  +    {
  +        "id": "1",
  +        "firstName": "John",
  +        "lastName": "Doe",
  +        "isRelatedTo": {
  +            "id": "2",
  +            "firstName": "Jane",
  +            "lastName": "Smith",
  +            "isRelatedTo": {
  +                "id": "1",
  +                "firstName": "John",
  +                "lastName": "Doe",
  +                "isRelatedTo": {
  +                    "id": "2",
  +                    "firstName": "Jane",
  +                    "lastName": "Smith",
  +                    "isRelatedTo": null
  +                }
  +            }
  +        }
  +    }
  +   */
   }
   
   // pretty JSON printer
  
positive.code:       });
  
    _prettyPrint(subject);
  }
  
  /*
  
negative.code:       .lens((template) => template.isRelatedTo.isRelatedTo.lastName = 'Pete');
  
    _prettyPrint(subject);
  
    /*
        {
            "id": "1",
            "firstName": "Billie",
            "lastName": "The Kid",
            "isRelatedTo": {
                "id": "2",
                "firstName": "Calamity",
                "lastName": "Jane",
                "isRelatedTo": {
                    "id": null,
                    "firstName": "Pistol",
                    "lastName": "Pete",
                    "isRelatedTo": null
                }
            }
        }
     */
  }
  
  /*
  