@CanIgnoreReturnValue
    public DuoSecurityUserAccount addDevice(final DuoSecurityUserDevice device) {
        this.devices.add(device);
        return this;
    }
Add devices.

@param device the device
@return the duo security user account
support/cas-server-support-duo-core-mfa/src/main/java/org/apereo/cas/adaptors/duo/DuoSecurityUserAccount.java