def _build_credentials(self, nexus_switches):
        """Build credential table for Rest API Client.

        :param nexus_switches: switch config
        :returns credentials: switch credentials list
        """
        credentials = {}
        for switch_ip, attrs in nexus_switches.items():
            credentials[switch_ip] = (
                attrs[const.USERNAME], attrs[const.PASSWORD],
                attrs[const.HTTPS_VERIFY], attrs[const.HTTPS_CERT],
                None)
            if not attrs[const.HTTPS_VERIFY]:
                LOG.warning("HTTPS Certificate verification is "
                            "disabled. Your connection to Nexus "
                            "Switch %(ip)s is insecure.",
                            {'ip': switch_ip})
        return credentials
Build credential table for Rest API Client.

        :param nexus_switches: switch config
        :returns credentials: switch credentials list