'Fetches the current version number of the Graph API being used.'

def get_version(self):

    args = {'access_token': self.access_token}
    try:
        response = self.session.request('GET', ((FACEBOOK_GRAPH_URL + self.version) + '/me'), params=args, timeout=self.timeout, proxies=self.proxies)
    except requests.HTTPError as e:
        response = json.loads(e.read())
        raise GraphAPIError(response)
    try:
        headers = response.headers
        version = headers['facebook-api-version'].replace('v', '')
        return float(version)
    except Exception:
        raise GraphAPIError('API    version    number    not    available')
