--- a/rust/src/sensor.rs	Wed Jan 04 17:18:44 2017 +0800
+++ b/rust/src/sensor.rs	Thu Jan 05 23:26:00 2017 +0800
@@ -17,11 +17,15 @@
 }
 
 pub struct OneWireSensor {
+    master_dir: String,
 }
 
 impl OneWireSensor {
     fn new() -> OneWireSensor {
-        OneWireSensor {}
+        OneWireSensor {
+            master_dir: String::new(), // XXX
+            
+        }
         // todo
     }
 
@@ -32,6 +36,11 @@
         debug!("sensor step {:?}", r);
         r
     }
+
+    fn sensor_names(self) -> Vec<String> {
+        let mut names = vec![];
+        names
+    }
 }
 
 impl Sensor for OneWireSensor {