Property 'hasOwnProperty' does not exist on type 'First'

[sidouglas]

I am looking through your code on https://ts.chibicode.com/refactor/

These generics don't seem to play well on TS 3.8.3

This snippet generates an error Property 'hasOwnProperty' does not exist on type 'First'

https://www.typescriptlang.org/play/#code/GYVwdgxgLglg9mABAUwB5WWAJgHgGIwBOAzlADSIDKyECWAfABQBQiiwRpAXIgSea0TEadHtVrZmASh59SiAGRUR2RAG9BE+YWTEQAGyg8ACgENCsU-vycoi5RIaIAvOoC+g4HEKJGWuwAOhHABiDBIHPxS6oJsMMC+kaQAdAAWpsQA8gDuYMbBAcgWAJ6MQSFS0RpsNb46eoaIGby2UgDa5QEAui7sth0FXbGIHmyj7N6+-oidYUjCjlXD8b4LdGkZOXkFRVClnZUxtWyM9QZ2zeJ07Z09rmvYAyFDtePjOlAghEhnjc1ydiUV0kHgg+gyxEQxiKxAQR0Q-kIIGg3jKIAARvoYBBEGBTABbZA8UiEcIAcyqHg84QwhGApggyEQABk4GSyaZMUzqoh9GzGHjCcSoKSwBSeAA3OAwLDMUHg4iQgDCCFh+mQrPZRTC+IC6sJYCgkM1HK58L5ZIFBKJQhF5KWtS0cHVyQtjAABgAJZD6PkUACSAHJ8YgACRqQXINzJd1SQRU5jTABWMBDrjQGGwLDYYGQ2ShMIQjEDAClU4GpGRBCqwGqNWyyUVkuUoHA9oVpMwU-jXfzu8lI1IgA

Otherwise thank you for providing such TS good learning resource.