diff --git a/src/main.rs b/src/main.rs
index 6b8abb4..a6316cc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -266,6 +266,7 @@ fn maybe_gzip_decode<R:Read>(input:R)->AResult<ReaderType<R>>{
 
 async fn upload_list(cookie:String,group:Option<u64>,asset_id_file_map:AssetIDFileMap)->AResult<()>{
 	let client=reqwest::Client::new();
+	//this is calling map on the vec because the closure produces an iterator of futures
 	futures::stream::iter(asset_id_file_map.into_iter()
 	.map(|(asset_id,file)|{
 		let client=&client;