code: def submit(self, form, url=None, **kwargs):
          
          if isinstance(form, Form):
              form = form.form
          response = self._request(form, url, **kwargs)
          Browser.add_soup(response, self.soup_config)
          return response
docs: Prepares and sends a form request.
  
          NOTE: To submit a form with a :class:`StatefulBrowser` instance, it is
          recommended to use :func:`StatefulBrowser.submit_selected` instead of
          this method so that the browser state is correctly updated.
  
          :param form: The filled-out form.
          :param url: URL of the page the form is on. If the form action is a
              relative path, then this must be specified.
          :param \\*\\*kwargs: Arguments forwarded to `requests.Session.request
              <http://docs.python-requests.org/en/master/api/#requests.Session.request>`__.
  
          :return: `requests.Response
              <http://docs.python-requests.org/en/master/api/#requests.Response>`__
              object with a *soup*-attribute added by :func:`add_soup`.