Elastica\Response::getError PHP Method

    public function getError()
    {
        $error = $this->getFullError();
        if (!$error) {
            return '';
        }
        if (is_string($error)) {
            return $error;
        }
        $rootError = $error;
        if (isset($error['root_cause'][0])) {
            $rootError = $error['root_cause'][0];
        }
        $message = $rootError['reason'];
        if (isset($rootError['index'])) {
            $message .= ' [index: ' . $rootError['index'] . ']';
        }
        if (isset($error['reason']) && $rootError['reason'] != $error['reason']) {
            $message .= ' [reason: ' . $error['reason'] . ']';
        }
        return $message;
    }

 /**
  * Construct Exception.
  *
  * @param \Elastica\Request  $request
  * @param \Elastica\Response $response
  */
 public function __construct(Request $request, Response $response)
 {
     $this->_request = $request;
     $this->_response = $response;
     parent::__construct($response->getError());
 }