Not for 'how-to' coding questions but PHP theory instead, this forum is here for those of us who wish to learn about design aspects of programming with PHP.
/**
* Class constructor. The profiler is disabled by default unless it is
* specifically enabled by passing in $enabled here or calling setEnabled().
*
* @param boolean $enabled
* @return void
*/
public function __construct($enabled = false)
{
$this->setEnabled($enabled);
}