### PullRefreshSample
```kotlin
@Composable
@OptIn(ExperimentalMaterialApi::class)
fun PullRefreshSample() {
    val refreshScope = rememberCoroutineScope()
    var refreshing by remember { mutableStateOf(false) }
    var itemCount by remember { mutableStateOf(15) }
    fun refresh() =
        refreshScope.launch {
            refreshing = true
            delay(1500)
            itemCount += 5
            refreshing = false
        }
    val state = rememberPullRefreshState(refreshing, ::refresh)
    Box(Modifier.pullRefresh(state)) {
        LazyColumn(Modifier.fillMaxSize()) {
            if (!refreshing) {
                items(itemCount) { ListItem { Text(text = "Item ${itemCount - it}") } }
            }
        }
        PullRefreshIndicator(refreshing, state, Modifier.align(Alignment.TopCenter))
    }
}
```