android room-如何将 set/println 转换为字符串？

我正在尝试将设置作为文本添加到电子邮件中

//Data class

@Entity(tableName = "inventory")
data class InventoryDataClass(
    @PrimaryKey(autoGenerate = true)
    var id: Int,
    @NonNull var itemNumber: String,
    @NonNull val itemDescription: String,
    val currentInventory: Int?,
    @NonNull val optimalInventory: Int,
    @NonNull val minInventory: Int
)

// getting list from room

    val inventoryList by mainViewModel.getInventoryItems.collectAsState(initial = emptyList())

//converting list to set

val emailNumber = inventoryList.map { item ->
println("Item Number: ${item.itemNumber} | Item Description: ${item.itemDescription} | Current Inventory: ${item.currentInventory.toString()}")}.toSet()

我能够得到我需要的输出：

I/System.out: Item Number: 123| Item Description: item1 | Current Inventory: 47
I/System.out: Item Number: 456| Item Description: item2 | Current Inventory: 8
...

如何将其作为字符串获取，并将其作为文本添加到电子邮件中？到目前为止，我只能找到科特林。单元

Log.d(TAG, "InventoryMainScreen: $emailNumber")
//output
D/MainActivity: InventoryMainScreen: [kotlin.Unit]