code: private function httpGet( $path, array $query = array() ){
  
          $url = new Uri( $this->baseUrl . $path );
  
          foreach( $query as $name => $value ){
              $url = Uri::withQueryValue($url, $name, $value );
          }
  
          //---
  
          $request = new Request(
              'GET',
              $url,
              $this->buildHeaders()
          );
  
          try {
  
              $response = $this->getHttpClient()->sendRequest( $request );
  
          } catch (\RuntimeException $e){
              throw new Exception\PostcodeException( $e->getMessage(), $e->getCode(), $e );
          }
  
          //---
  
          if( $response->getStatusCode() != 200 ){
              throw $this->createErrorException( $response );
          }
  
          return $response;
  
      }
docs: Performs a GET against the API.
  
  @param string $path
  @param array  $query
  
  @return ResponseInterface
  @throw Exception\PostcodeException | Exception\ApiException | Exception\UnexpectedValueException