@Override
    protected Ini getFrameworkIni() {
        if (otherConfigLocation != null) {
            return createIni(otherConfigLocation, true);
        } else {
            return super.getFrameworkIni();
        }
    }
Ability to merge two configuration files, exactly two
support/jakarta-ee/src/main/java/org/apache/shiro/ee/listeners/IniEnvironment.java