sendFileMessages

channel.sendFileMessages(paramsList)
    .onEach {
        when (it) {
            is MultipleMessagesResult.Pending -> {
                // called it when sending file messages are started
                // it contains pendingMessageList
            }
            is MultipleMessagesResult.EachSucceed -> {
                // each file sending completed
                // it.message is a succeeded file message
            }
            is MultipleMessagesResult.EachFailure -> {
                // each file sending failed
                // it.failedMessage is a failed file message
                // it.e is a cause of failure
            }
        }
    }.catch {
        // called it when request failed (validation failure)
    }.onCompletion {
        // called it when all all file messages are completed
    }.launchIn(viewModelScope)