/**
  * Checks the travel modes getter
  */
 public function testTravelModes()
 {
     $this->assertEquals(TravelMode::getTravelModes(), array(TravelMode::BICYCLING, TravelMode::DRIVING, TravelMode::WALKING));
 }
 /**
  * Sets the directions request travel mode
  *
  * @param string $travelMode
  */
 public function setTravelMode($travelMode = null)
 {
     if (in_array($travelMode, TravelMode::getTravelModes()) || is_null($travelMode)) {
         $this->travelMode = $travelMode;
     } else {
         throw new \InvalidArgumentException(sprintf('The directions request travel mode can only be : %s', implode(', ', TravelMode::getTravelModes())));
     }
 }