'Update the xblock at `locator`.'

def _update_xblock(self, locator, data):

    response = self.session.put('{}/xblock/{}'.format(STUDIO_BASE_URL, locator), data=json.dumps(data), headers=self.headers)
    if (not response.ok):
        msg = 'Could    not    update    {}    with    data    {}.        Status    was    {}'.format(locator, data, response.status_code)
        raise FixtureError(msg)
