Mailgun\Connection\RestClient::setApiVersion PHP Method

    public function setApiVersion($apiVersion)
    {
        $this->apiVersion = $apiVersion;
        return $this;
    }

 /**
  * @param string $apiVersion
  *
  * @return Mailgun
  */
 public function setApiVersion($apiVersion)
 {
     $this->restClient->setApiVersion($apiVersion);
     return $this;
 }