/**
  * Sets if the the distance matrix request avoids tolls.
  *
  * @param boolean $avoidTolls TRUE if the distance matrix request avoids tolls else FALSE.
  *
  * @throws \Ivory\GoogleMap\Exception\DistanceMatrixException If the avoid tolls flag is not valid.
  */
 public function setAvoidTolls($avoidTolls = null)
 {
     if (!is_bool($avoidTolls) && $avoidTolls !== null) {
         throw DistanceMatrixException::invalidDistanceMatrixRequestAvoidTolls();
     }
     $this->avoidTolls = $avoidTolls;
 }