Add route enhancers to the router to let them generate information on matched routes.
The order of the enhancers is determined by the priority, the higher the value, the earlier the enhancer is run.
RouteEnhancerInterface $enhancer:
int $priority:
public function addRouteEnhancer(RouteEnhancerInterface $enhancer, $priority = 0) {
if (empty($this->enhancers[$priority])) {
$this->enhancers[$priority] = array();
}
$this->enhancers[$priority][] = $enhancer;
$this->sortedEnhancers = array();
return $this;
}