AdminModule Code queation

[Sim]

private function getModule($moduleName = false) {
            if ($moduleName) {
                return $this->page->modules[$moduleName];
            } 

            return $this->page->modules;
        }

The above code is the function 

The below code shows the function accepting 2 parameters. 

 

            $this->html .= $this->page->buildElement("moduleList", array(
                "modules" => $this->getModule($this->methodData->moduleName, true)
            ));

 

Maybe theres new PHP rules in place or ????