close all streams when closing the IETF QUIC streams map

streams_map_generic_helper.go

@@ -0,0 +1,11 @@
+package quic
+
+import "github.com/cheekybits/genny/generic"
+
+// In the auto-generated streams maps, we need to be able to close the streams.
+// Therefore, extend the generic.Type with the stream close method.
+// This definition must be in a file that Genny doesn't process.
+type item interface {
+	generic.Type
+	closeForShutdown(error)
+}