public final class Trees {


    /**
     * Node of a binary search tree
     * Left subtree contains values that are less (or equal) than value of this node
     * Right subtree contains values that are greater than a value of this node
     */
    //FIXME Make this type safe using generics
    public interface Node {

        /**
         * Returns value associated with this node
         */
        Comparable value();

        /**
         * Returns left subtree if present
         */
        Node left();

        /**
         * Returns right subtree if present
         */
        Node right();

    }

    /**
     * Check whether tree contains provided value
     * @return true if value present in the tree
     */
    static boolean contains(Node tree, Comparable a) {
        //FIXME Provide implementation
        return false;
    }

    /**
     * Find a tree node that is Least Common Ancestor (com.example.LCA) for
     * provided values
     *
     * @param searchTree root node of a binary search tree
     * @param a    one of thee nodes in a tree
     * @param b    one of thee nodes in a tree
     * @return com.example.LCA
     */
    public static Node findLCA(Node searchTree, Node a, Node b) {
        //FIXME Provide implementation
        return null;
    }


    public static Node bfs(Node tree, Node a) {
        //FIXME Provide implementation
        return null;
    }
}