public String toResourceString(final Object arg) {
        if (auditFormat == AuditTrailManager.AuditFormats.JSON) {
            return AuditTrailManager.toJson(arg);
        }
        return resourceString != null
            ? this.resourceString + List.of(arg)
            : arg.toString();
    }
To resource string.

@param arg the arg
@return the string
core/cas-server-core-audit-api/src/main/java/org/apereo/inspektr/audit/spi/support/FirstParameterAuditResourceResolver.java