I have a function that is, custom_pagination() what I have placed in extras.php. When I call this function into the custom template, it does not work. If I placed this function at the bottom of functions.php, it works. I can see in functions.php that it is written in the comment that custom functions should be placed in extras.php. Can you tell me someone how should I call the custom functions from extras.php to custom template or page or anywhere in the theme.