{
    "name": "sergei/module-main",
    "version": "1.0.0",
    "type": "metapackage",
    "require": {
        "sergei/module-one": "1.0.0",
        "sergei/module-two": "1.0.0"
    }
}

sergei/module-one (Sergei_One in registration.php)
sergei/module-two (Sergei_Two in registration.php)