Basho\Riak\Node\Config::setCaDirectory PHP Method

    public function setCaDirectory($ca_directory)
    {
        $this->ca_directory = $ca_directory;
    }

 /**
  * withCertificateAuthorityDirectory
  *
  * Directory where the CA file can be found. A Certificate Authority file is required for any secure connections to
  * Riak
  *
  * @param $ca_directory
  *
  * @return $this
  *
  */
 public function withCertificateAuthorityDirectory($ca_directory)
 {
     $this->config->setCaDirectory($ca_directory);
     return $this;
 }