Where is forming HEADERF and FOOTERF in e107 v2? [closed]

I want to implements my html theme from themeforest into E107v2, but i cant find where if produce HEADERF and FOOTERF in e107 v2?

into custom page i use this code:

…..

include_once(HEADERF);

eFront::instance()->getResponse()->send(‘default’, false, true);

include_once(FOOTERF);

exit;

where can i change HEADERF and FOOTERF?