code: function (originalObj, originalProp, targetObj, targetProp) {
                  Object.defineProperty(
                      originalObj,
                      originalProp,
                      {
                          get: function () {
                              return targetObj[targetProp];
                          },
                          set: function (newValue) {
                              console.error(targetProp + ' is read-only.');
                              throw new Error('ReadOnly');
                          }
                      }
                  );
              }
docs: A read-only version of proxy, see above.