1. Assume that general trees are implemented using a Treenode class that includes the following fields and methods: // fields private T data; private List children; // methods public T getData() ( return data; ) public List > getChildren() { return children; ) For efficiency, use an iterator to access the children in the list returned by the method gotChildren (as we've done in lecture). You may assume that getChildren never returns null: if a node is a leaf, then getChildren will return a non-null list containing zero elements. Write an isBinary method whose header is given below. public boolean isBinary( TreenodecT> n) The method should determine if the general tree rooted by n is also a binary tree. A binary tree is recursively defined as: o An empty tree is binary. o A leaf node is a binary tree. A node with 1 or 2 children is binary if each child is itself a binary tree.