nsIInputIterator Interface

 Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
 The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.

 @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator

nsISupports clone()

 Retrieve (and |AddRef()|) the element this iterator currently points to.

 The result is undefined if this iterator currently points outside the
 useful range of the underlying container or sequence.

 @result a new reference to the element this iterator currently points to (if any)

nsISupports getElement()

 Test if |anotherIterator| points to the same position in the underlying container or sequence.

 The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.

 @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
 @result true if |anotherIterator| points to the same position in the underlying container or sequence

boolean isEqualTo(in nsISupports anotherIterator)

 Advance this iterator to the next position in the underlying container or sequence.

void stepForward()