nsIRandomAccessIterator in Firefox 2.0

 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

 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)

 Retrieve (and |AddRef()|) an element at some offset from where this iterator currently points.
 The offset may be negative.  |getElementAt(0)| is equivalent to |getElement()|.

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

 @param anOffset a |0|-based offset from the position to which this iterator currently points
 @result a new reference to the indicated element (if any)

 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

 Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
 The iterator and the underlying container or sequence cooperate to |Release()|
 the replaced element, if any and if necessary, and to |AddRef()| the new element.

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

 @param anElementToPut the element to place into the underlying container or sequence

 Put |anElementToPut| into the underlying container or sequence at the position |anOffset| away from that currently pointed to by this iterator.
 The iterator and the underlying container or sequence cooperate to |Release()|
 the replaced element, if any and if necessary, and to |AddRef()| the new element.
 |putElementAt(0, obj)| is equivalent to |putElement(obj)|.

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

 @param anOffset a |0|-based offset from the position to which this iterator currently points
 @param anElementToPut the element to place into the underlying container or sequence

 Move this iterator to the previous position in the underlying container or sequence.

 Move this iterator backwards by |anOffset| positions in the underlying container or sequence.
 |anOffset| may be negative.  |stepBackwardBy(1)| is equivalent to |stepBackward()|.
 |stepBackwardBy(n)| is equivalent to |stepForwardBy(-n)|.  |stepBackwardBy(0)| is a no-op.

 @param anOffset a |0|-based offset from the position to which this iterator currently points

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

 Move this iterator by |anOffset| positions in the underlying container or sequence.
 |anOffset| may be negative.  |stepForwardBy(1)| is equivalent to |stepForward()|.
 |stepForwardBy(0)| is a no-op.

 @param anOffset a |0|-based offset from the position to which this iterator currently points