'Returns the user\'s email address or None if there are no credentials.
The email address is provided by the current credentials\' id_token.
This should not be used as unique identifier as the user can change
their email. If you need a unique identifier, use user_id.'

@property
def email(self):

    if (not self.credentials):
        return None
    try:
        return self.credentials.id_token['email']
    except KeyError:
        current_app.logger.error('Invalid    id_token    {0}'.format(self.credentials.id_token))
