A modern programming language that makes developers happier.

kotlinlang

Could you please explain me, why it is so:
```
    var fullTariffList = mutableListOf&lt;TariffInfo&gt;()

    var testTariffList = listOf(TariffInfo(name="tariff_1"), TariffInfo(name="tariff_2"))

    testTariffList.forEach{ tariffInfo -&gt;
        arrayOf("customer", "reseller", "vendor").forEach {tariffInfo.type = it; println(tariffInfo); fullTariffList.add(tariffInfo)}
    }
  println(fullTariffList);
```
```
TariffInfo(type=customer, name=tariff_1)
TariffInfo(type=reseller, name=tariff_1)
TariffInfo(type=vendor, name=tariff_1)
TariffInfo(type=customer, name=tariff_2)
TariffInfo(type=reseller, name=tariff_2)
TariffInfo(type=vendor, name=tariff_2)
[TariffInfo(type=vendor, name=tariff_1), TariffInfo(type=vendor, name=tariff_1), TariffInfo(type=vendor, name=tariff_1), TariffInfo(type=vendor, name=tariff_2), TariffInfo(type=vendor, name=tariff_2), TariffInfo(type=vendor, name=tariff_2)]
```