'Add commonly used values such as access_token to self.'

def _populate_attributes(self, response):

    if (u'access_token' in response):
        self.access_token = response.get(u'access_token')
    if (u'refresh_token' in response):
        self.refresh_token = response.get(u'refresh_token')
    if (u'token_type' in response):
        self.token_type = response.get(u'token_type')
    if (u'expires_in' in response):
        self.expires_in = response.get(u'expires_in')
    if (u'code' in response):
        self.code = response.get(u'code')
