Query Lambda's DescribeLimits API action, and update limits
        with the quotas returned. Updates ``self.limits``.

def _update_limits_from_api(self):
        """
        Query Lambda's DescribeLimits API action, and update limits
        with the quotas returned. Updates ``self.limits``.
        """
        logger.debug("Updating limits for Lambda from the AWS API")
        if len(self.limits) == 2:
            return
        self.connect()
        lims = self.conn.get_account_settings()['AccountLimit']
        self.limits['Total Code Size (MiB)']._set_api_limit(
            (lims['TotalCodeSize']/1048576))
        self.limits['Code Size Unzipped (MiB) per Function']._set_api_limit(
            (lims['CodeSizeUnzipped']/1048576))
        self.limits['Unreserved Concurrent Executions']._set_api_limit(
            lims['UnreservedConcurrentExecutions'])
        self.limits['Concurrent Executions']._set_api_limit(
            lims['ConcurrentExecutions'])
        self.limits['Code Size Zipped (MiB) per Function']._set_api_limit(
            (lims['CodeSizeZipped']/1048576))