[pkg-php-pear] How to replace "require vendor/autoload.php" in deb package

[Fab]

Hello,

If a project uses:

require_once vendor/autoload.php

to autoload the classes defined in composer.json, how should that be changed 
when doing a debian package so that it uses the debian php packages installed 
on the system?

Should it be changed to as many such lines as needed?

require_once /usr/share/php/pkg1/autoload.php
require_once /usr/share/php/pkg2/autoload.php
require_once /usr/share/php/pkg3/autoload.php

Or is there a way to make it single-lined like this?
require_once /usr/share/php/Composer/autoload.php
(I guess we can't install pkg1, pkg2... into /usr/share/php/Composer)


Thanks
Fab