php如何在内部引用私有方法

<?php
class Person {
 public function say($name, $age) {
 $con = $this->get($name, $age); //这里的$this->是关键
 echo "my name is :".$name."<br />";
 echo "my age is :".$age."<br/>";
 echo "get :".$con."<br/>";
 }
 private function get($a, $b) {
 $a = $a.$b;
 return $a;
 }
}
$person=new Person();
$person->say("ren", 25);
?>