Call graph generation with PHPCallGraph:
    phpcallgraph -f png -o callgraphs/functions-07.png functions.php classes
Some regular expressions used for refactoring with VIM:
    :%s/function /public static function /gc
    :%s/=\([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*\)(/ = self::\1(/gc
    :%s/\([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*javascript[a-zA-Z0-9_\x7f-\xff]*\)(/JavaScript::\1(/gc
    :%s/print_javascript_alert/getAlert/gc
    :%s/draw_javascript/getScriptElement/gc
    :%s/draw_javascript_backlink/getBackLink/gc
    :%s/draw_javascript_buttonlink/getButtonLink/gc
    :%s/draw_javascript_to_change_status/changeStatus/gc
    :%s/draw_javascript_to_image_src/changeImageSource/gc
Automatic generation of a test case for the timer class with PHPUnit:
    cd tests
    phpunit --skeleton Timer ../classes/Timer.php
Execution of test case via:
    cd tests
    phpunit TimerTest