1. What exception might next throw? Is it a checked exception or unchecked exception (RuntimeException)? 2. For an Iterator, what is the return type of hasNext? 3. For an Iterator, what is the return type of next? 4. What does this program print? class Mysterator implements Iterator private int nextValue; public Mysterator(int start) public boolean hasNext(O public Integer next) nextvalue = start ; return nextValue 64 int result = nextvalue; nextvalue *= 2; return result; public static void main(String[] args) IteratorInteger> it = new Mysterator ( 2); while (it.hasNext(O) System.out.println(it.next)) What is the useful invariant of the above iterator? Write it in the following form (two blanks). 5