observePriceUpdateFlow.kt

    private suspend fun observePriceUpdateFlow(index: Int, currencyPriceUpdateFlow: Flow<Int>) {
        currencyPriceUpdateFlow.collect { newPrice ->
            val newFluctuation = when {
                newPrice > _currencyPrices.value[index].price -> PriceFluctuation.UP
                else -> PriceFluctuation.DOWN
            }
            val updatedCurrencyPrice = _currencyPrices.value[index].copy(
                price = newPrice,
                priceFluctuation = newFluctuation
            )
            val mutableCurrencyPrices = _currencyPrices.value.toMutableList()
            mutableCurrencyPrices[index] = updatedCurrencyPrice
            _currencyPrices.value = mutableCurrencyPrices.toList()
        }
    }