+ reimplement virtual methods in PropertyExpressionEngine

src/App/PropertyExpressionEngine.cpp

@@ -739,3 +739,13 @@ std::set<ObjectIdentifier> PropertyExpressionEngine::getPaths() const
 
     return result;
 }
+
+PyObject *PropertyExpressionEngine::getPyObject(void)
+{
+    Py_Return;
+}
+
+void PropertyExpressionEngine::setPyObject(PyObject *)
+{
+    throw Base::RuntimeError("Property is read-only");
+}

src/App/PropertyExpressionEngine.h

@@ -120,6 +120,10 @@ public:
 
     void slotObjectRenamed(const App::DocumentObject & obj);
 
+    /* Python interface */
+    PyObject *getPyObject(void);
+    void setPyObject(PyObject *);
+
 private:
 
     typedef boost::adjacency_list< boost::listS, boost::vecS, boost::directedS > DiGraph;