PayPal\Api\Phone::getExtension PHP Method

    public function getExtension()
    {
        return $this->extension;
    }

 /**
  * @depends testSerializationDeserialization
  * @param Phone $obj
  */
 public function testGetters($obj)
 {
     $this->assertEquals($obj->getCountryCode(), "TestSample");
     $this->assertEquals($obj->getNationalNumber(), "TestSample");
     $this->assertEquals($obj->getExtension(), "TestSample");
 }