Consider the following declarations when answering parts h: class b_node {public: string client; b_node *right, *left;}; class BST {public: BST(); int Count_Nodes_with_Two_Children (b_node *r); private: b_node *root;}; h. Implement the recursive function called "Count_Nodes_with_Two_Children" that returns an integer representing the number of nodes with two children in a binary search tree given a pointer to the root of the tree. Assume that the function is originally invoked by another member function