anchor.diff:        });
   
     _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
  +              }
  +          }
  +      }
  +   */
   }
   
   /*
  
positive.code:       .lens((template) => template.isRelatedTo.isRelatedTo.lastName = 'Pete');
  
    _prettyPrint(subject);
  }
  
  /*
  
negative.code:       .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
  