code: public function requestContent(string $method, string $uri, ?array $get = null, ?array $post = null, ?array $files = null, ?array $headers = null)
      {
          $options = $this->prepareOptions($get, $post, $files, $headers);
  
          return (string) $this->request($method, $uri, $options)->getBody();
      }
docs: @param string     $method
  @param string     $uri
  @param array|null $get
  @param array|null $post
  @param array|null $files
  @param array|null $headers
  
  @throws GuzzleException
  
  @return string