:param request: OAuthlib request.
        :type request: oauthlib.common.Request

def validate_scopes(self, request):
        """
        :param request: OAuthlib request.
        :type request: oauthlib.common.Request
        """
        if not request.scopes:
            request.scopes = utils.scope_to_list(request.scope) or utils.scope_to_list(
                self.request_validator.get_default_scopes(request.client_id, request))
        log.debug('Validating access to scopes %r for client %r (%r).',
                  request.scopes, request.client_id, request.client)
        if not self.request_validator.validate_scopes(request.client_id,
                                                      request.scopes, request.client, request):
            raise errors.InvalidScopeError(request=request)