I checked bellow.
https://github.com/concrete5/concrete5-5.7.0/wiki/Migration-Guide...

Also I checked "Use PHP Namespacing instead of Loader functions" and "http://andrewembler.com/posts/concrete5-5-7-add-on-development-part-1/"

But I am not sure.

My head of code are bellow in packages/libraries/tomoacfunc.php in concrete5.6
--
<?php defined('C5_EXECUTE') or die(_("Access Denied."));
class TomoacFunc {
--
It calls
Loader::library('tomoacfunc','tomoac_handle')

How should change code for 5.7