/// \brief prints any type of entry to the entry set (pure vitual)
virtual void Print (std::ostream & os = std::cout) = 0;// pure virtual
/// \brief write any type of entry to the entry set
/// \brief prints any type of entry to the entry set (pure vitual)
virtual void Print (std::ostream & os = std::cout) = 0;// pure virtual
/// \brief write any type of entry to the entry set