This example adds a new function `tx_myextension_modulefunc` to the `web_func` module. The function code is located in `path/to/myextension/modfunc_file.php`. The function's label is "My Extension - My Function". This code example is from an extension package library that helps developers add new functionality to TYPO3 CMS. The specific package library could be any combination of extensions that includes t3lib_extMgm.