code: public function withoutHeader($header)
      {
          $object = clone $this;
          $headerName = $object->normalizeHeaderName($header);
          if (isset($this->configs['headers'][$headerName])) {
              unset($this->configs['headers'][$headerName]);
          }
  
          $object->request = $object->request->withoutHeader($headerName);
          return $object->buildConfigClient();
      }
docs: With Added Current Headers
  
  @param mixed $header
  @return static