Given this error:

at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72)

at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72)

at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72) at Stack.peek(Stack.java:72)

Please fix this method in Java:

public T peek() {

// return the top of the Stack (but don't remove it)

// if there are no items on the Stack, return null

// O(1)

if (isEmpty()) {

return null;

}

return this.peek();

}