upgradeExternalFirmware(mac, firmware_url) {
    const payload = {url: firmware_url,
      mac: mac.toLowerCase()};

    return this._request('/api/s/<SITE>/cmd/devmgr/upgrade-external', payload);
  }
/**
   * Upgrade External Firmware (5.4.9+)
   *
   * required parameter <mac>          = device MAC address
   * required parameter <firmware_url> = external URL to firmware data
   *
   */
Upgrade External Firmware (5.4.9+)
required parameter           = device MAC address
required parameter  = external URL to firmware data
Upgrade External Firmware ( 5 . 4 . 9 + ) required parameter = device MAC address required parameter = external URL to firmware data
upgradeExternalFirmware(mac, firmware_url) {
    const payload = {url: firmware_url,
      mac: mac.toLowerCase()};
    return this._request('/api/s/<SITE>/cmd/devmgr/upgrade-external', payload);
  }
upgradeExternalFirmware ( mac , firmware_url ) { const payload = { url : firmware_url , mac : mac . toLowerCase ( ) } ; return this . _request ( '/api/s/<SITE>/cmd/devmgr/upgrade-external' , payload ) ; }
Upgrade External Firmware (5.4.9+)
 required parameter <mac>          = device MAC address
 required parameter <firmware_url> = external URL to firmware data
Upgrade External Firmware ( 5 . 4 . 9 + ) required parameter <mac > = device MAC address required parameter <firmware_url > = external URL to firmware data