Matched Python APIs: Device is not abstract. (#319)

Author: ATATC

src/Device.h

@@ -19,9 +19,9 @@ class Device {
     void parentTags(const ArrayList<String> &parentTags) { _parentTags = parentTags; }
     const ArrayList<String> &parentTags() { return _parentTags; }
     virtual void initialize(const ArrayList<String> &parentTags) { _parentTags = parentTags; }
-    virtual T read() = 0;
-    virtual void write(T payload) = 0;
-    virtual void update(T data) = 0;
+    virtual T read() { return T(); }
+    virtual void write(T payload) {}
+    virtual void update(T data) {}
     virtual void close() {}
 };