MuonTesterTree --- Use MSG macros and inherit from AthMessasing

MuonSpectrometer/MuonValidation/MuonTesterTree/MuonTesterTree/MatrixBranch.h

 /*
-  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 */
 #ifndef MUONTESTER_MATRIXBRANCH_H
 #define MUONTESTER_MATRIXBRANCH_H
@@ -9,7 +9,7 @@ class TTree;
 
 namespace MuonVal {
 class MuonTesterTree;
-template <class T> class MatrixBranch : public IMuonTesterBranch {
+template <class T> class MatrixBranch : public MuonTesterBranch, virtual public IMuonTesterBranch {
 public:
     /// Standard constructor
     MatrixBranch(TTree* tree, const std::string& name);
@@ -19,18 +19,11 @@ public:
     MatrixBranch(TTree* tree, const std::string& b_name, const T& def);
     MatrixBranch(MuonTesterTree& tree, const std::string& b_name, const T& def);
 
-    MatrixBranch(const MatrixBranch&) = delete;
-    void operator=(const MatrixBranch&) = delete;
+
     virtual ~MatrixBranch() = default;
 
     bool fill(const EventContext& ctx) override final;
     bool init() override final;
-    std::string name() const override final;
-
-    std::vector<DataDependency> data_dependencies() override final;
-
-    const TTree* tree() const override final;
-    TTree* tree() override final;
 
     bool initialized() const;
 
@@ -56,6 +49,7 @@ public:
 private:
     VectorBranch<std::vector<T>> m_Vec;
     T m_default;
+    MuonTesterTree* m_parent{nullptr};
 };
 }
 #include <MuonTesterTree/MatrixBranch.icc>