C++ only and follow instructionsHere is a C++ class definition for an abstract data type WordTree of string objects. You must store the words and the counts of the words in a single binary search tree. Each word occurring in the text can only be stored once in the tree. Implement each member function in the class below. The WordTree class may have only one member variable, root, and it must be private. You may add additional private members functions to the WordTree class. Some of the functions we may have already done in lecture, that's fine, try to do those first without looking at your notes. Remember to provide an appropriate copy constructor, destructor and assignment operator for the WordTree class as well.#include #include typedef std::string WordType;struct WordNode { WordType m_data; WordNode *m_left; WordNode *m_right; // You may add additional data members and member functions // in WordNode};