Symfony\Component\DomCrawler\Form::getMethod PHP Method

    public function getMethod()
    {
        if (null !== $this->method) {
            return $this->method;
        }

        // If the form was created from a button rather than the form node, check for HTML5 method override
        if ($this->button !== $this->node && $this->button->getAttribute('formmethod')) {
            return strtoupper($this->button->getAttribute('formmethod'));
        }

        return $this->node->getAttribute('method') ? strtoupper($this->node->getAttribute('method')) : 'GET';
    }

 protected function makeRequestUsingForm(Form $form)
 {
     $files = [];
     $plainFiles = $form->getFiles();
     foreach ($plainFiles as $key => $file) {
         $files[$key] = new UploadedFile($file['tmp_name'], $file['name'], $file['type'], $file['size'], $file['error'], true);
     }
     return $this->makeRequest($form->getMethod(), $form->getUri(), $form->getValues(), [], $files);
 }