def Refresh(self):
    if self.credentials is None:
      raise RefreshError('No credential to refresh.')
    if self.credentials.refresh_token is None:
      raise RefreshError('No refresh_token found.'
                         'Please set access_type of OAuth to offline.')
    if self.http is None:
      self.http = httplib2.Http(timeout=self.http_timeout)
    try:
      self.credentials.refresh(self.http)
    except AccessTokenRefreshError as error:
      raise RefreshError('Access token refresh failed: %s' % error)
Refreshes the access_token.
dataset/ETHPy150Open googledrive/PyDrive/pydrive/auth.py/GoogleAuth.Refresh