suspend function が利用できる map

LiveDataExt.kt

inline fun <T, U> LiveData<T>.map(
    scope: CoroutineScope,
    crossinline block: suspend (T) -> U
): LiveData<U> {
    val result = MediatorLiveData<U>()
    result.addSource(this) {
        scope.launch {
            result.postValue(block.invoke(it))
        }
    }
    return result
}