improvements, start using in example

satrs/tests/mode_tree.rs

@@ -502,7 +502,7 @@ impl ModeRequestHandler for AcsSubsystem {
             .unwrap();
         self.mode_node
             .send_mode_reply(requestor_info, reply)
-            .map_err(ModeError::Messaging)?;
+            .map_err(ModeError::Send)?;
         Ok(())
     }
 }