Given the following Java code, assuming no syntax errors, please provide answers for (a) and (b). Thank you!

Tree Software 6. Given the following Java code fragment, implement the requested methods. You may not introduce any new class level variables. Assume no syntax errors. public class BasicTree [ private class Node t K key; V value; public Node (K key, V value) this.key - key; this.valuevalue; Node root; int curSize; * Produces the key sequence resulting from a pre-order tree *traversal *Greturn A List of the keys in the tree in pre-order public List preOrderKeys O TODO Student Code 4a *Helper function for public recursive method private List preOrderKeys (Node start) TODO Student Code Tree Software 6. Given the following Java code fragment, implement the requested methods. You may not introduce any new class level variables. Assume no syntax errors. public class BasicTree [ private class Node t K key; V value; public Node (K key, V value) this.key - key; this.valuevalue; Node root; int curSize; * Produces the key sequence resulting from a pre-order tree *traversal *Greturn A List of the keys in the tree in pre-order public List preOrderKeys O TODO Student Code 4a *Helper function for public recursive method private List preOrderKeys (Node start) TODO Student Code