Adds a Matcher to the index.
MatcherInterface $matcher: The matcher to add.
int $priority: (optional) The priority of the matcher. Higher number matchers will be checked first. Default to 0.
public function add(RequestMatcherInterface $matcher, $priority = 0) {
if (empty($this->matchers[$priority])) {
$this->matchers[$priority] = array();
}
$this->matchers[$priority][] = $matcher;
$this->sortedMatchers = array();
}