Given an Iterator class interface with methods: next() and hasNext(), design and implement a PeekingIterator that support the peek() operation – it essentially peek() at the element that will be returned by the next call to next().

class PeekingIterator implements Iterator<Integer> {
    Integer nextElement;
    Iterator<Integer> iterator;
    public PeekingIterator(Iterator<Integer> iterator) {
        this.iterator = iterator;
        nextElement = null;
    }

    public Integer peek() {
        if (nextElement == null) {
            nextElement = iterator.next();
        }
        return nextElement;
    }

    @Override
    public Integer next() {
        if (nextElement == null) {
            return iterator.next();
        } else {
            int result = nextElement;
            nextElement = null;
            return result;
        }
    }

    @Override
    public boolean hasNext() {
        return nextElement != null || iterator.hasNext();
    }
}

class PeekingIterator(object):
    def __init__(self, iterator):
        self.iterator = iterator
        self.next_element = None

    def peek(self):
        if self.next_element is None:
            self.next_element = self.iterator.next()
        return self.next_element

    def next(self):
        if self.next_element is None:
            return self.iterator.next()
        else:
            ret = self.next_element
            self.next_element = None
            return ret

    def hasNext(self):
        return self.next_element is not None or self.iterator.hasNext()