src/Core/HttpClients/CurlHttpClient.php
private function getHeaders($headers){
      if(!isset($headers) || empty($headers)){
          throw new SdkException("Error. The headers set for cURL are either NULL or Empty");
      }else{
          $convertedHeaders = $this->convertHeaderArrayToHeaders($headers);
          return $convertedHeaders;
      }
    }
private function getHeaders($headers){
      if(!isset($headers) || empty($headers)){
          throw new SdkException("Error. The headers set for cURL are either NULL or Empty");
      }else{
          $convertedHeaders = $this->convertHeaderArrayToHeaders($headers);
          return $convertedHeaders;
      }
    }
Get headers for the QuciKbooks Online Response