text: #include "geometry/Vector3D.h"
  #include "utils/observables/Observer.h"
  #include "geometry/numeric/eig3.h"
  
  #ifndef TENSORIAL_H
  #define TENSORIAL_H
  
  class Tensorial : public Observer
  {
      public:
          explicit Tensorial(const char*, const char*);
          Tensorial(const Tensorial& orig);
          virtual ~Tensorial();
  
          double observe(const Box&, const std::vector<Shell>&);
  
      private:
          static DerivedRegister<Tensorial> reg;
  };
  
  #endif /* TENSORIAL_H */
  
  