Ex$4.$Extract subtree

$(20$ points$)$

Write a BST member function Copy$\_$subTree$($self$,n)$ to extract and return a subtree rooted by $n.$ For example, on the following tree, the function should return the subtree shown to the right.

ne current tree the returned bsy the current Tree after calling the function

$(7.)$

$(2)$

$(9)$

$(3)$