ENH : comment

Code/IO/otbDefaultImageMetadataInterfaceFactory.h

@@ -28,6 +28,7 @@ namespace otb
 {
 /** \class DefaultImageMetadataInterfaceFactory
  * \brief Creating an instance of a ImageMetadataInterface object using object factory.
+ * This class only provides the method of the virtual pure class ImageMetadataInterfaceBase and throw exception for virtual method.
  */
 class ITK_EXPORT DefaultImageMetadataInterfaceFactory : public itk::ObjectFactoryBase
 {