Fixed merge issue, class was not defined in header file

core/XdmfArray.cpp

@@ -464,6 +464,7 @@ private:
   XdmfArray * const mArray;
 };
 
+
 class XdmfArray::IsInitialized : public boost::static_visitor<bool> {
 public:
 

core/XdmfArray.hpp

@@ -1552,6 +1552,7 @@ private:
   template <typename T> class Insert;
   class InsertArray;
   class InternalizeArrayPointer;
+  class IsInitialized;
   struct NullDeleter;
   template <typename T> class PushBack;
   class Reserve;