ENH: add missing method

Code/ApplicationEngine/otbWrapperParameterGroup.h

@@ -67,6 +67,12 @@ public:
 
   std::vector<std::string> GetParametersKeys(bool recursive = true);
 
+  // Always has value
+  bool HasValue() const
+  {
+    return true;
+  }
+
 protected:
   ParameterGroup();
   virtual ~ParameterGroup();

Code/ApplicationEngine/otbWrapperRadiusParameter.h

@@ -44,6 +44,11 @@ public:
   /** RTTI support */
   itkTypeMacro(RadiusParameter, Parameter);
 
+  bool HasValue() const
+  {
+    return true;
+  }
+
 protected:
   /** Constructor */
   RadiusParameter()