VideoViewModel.kt

@HiltViewModel
class VideoViewModel @Inject constructor(
    private val repository: VideoRepository
) : ViewModel() {

    val items: Flow<PagingData<VideoWithChannelModel>> = Pager(
        PagingConfig(10, enablePlaceholders = false),
        pagingSourceFactory = { repository.videosPagingSource() }
    ).flow
        .map { value: PagingData<Item> -> //map function from kotlinx.coroutines.flow
            value.map {  // map function in androidx.paging
                val channelUrl = onChannelImgRequired(it.snippet.channelId.toString())
                VideoWithChannelModel(it, channelUrl)
            }
        }
        .cachedIn(viewModelScope)


    private suspend fun onChannelImgRequired(channelId: String): String {
        return repository.loadChannelThumbnail(channelId)
    }

}

data class VideoWithChannelModel(
    val item: Item,
    val channelUrl: String
)