Symphony.

/**
 * The initialise function will set the exception_handler to the this class's
 * handler function
 */
public static function initialise($Log = null){
    if(!is_null($Log)){
        self::$_Log = $Log;
    }
    set_exception_handler(array(__CLASS__, 'handler'));
}

/**
 * The initialise function will set the exception_handler to the this class's
 * handler function
 *
 * @param Log|null $log
 *  An instance of a Symphony Log object to write errors to
 */

public static function initialise(Log $Log = null){
    if(!is_null($Log)){
        self::$_Log = $Log;
    }
    set_exception_handler(array(__CLASS__, 'handler'));
}