Lazy Loading in PHP info
Lazy Loading in PHP with Closures: http://verraes.net/2011/05/lazy-loading-with-closures/
As we have seen the definition, lazy loading will help preventing any initialization until it’s being used. http://codesamplez.com/programming/php-closure-tutorial
Closures in PHP: https://blog.eduonix.com/web-programming-tutorials/closures-in-php/