erator2 = <a href="#type-iterator">iterator</a>(Elem | NewTuple)</tt></li></ul></p>
<p> </p>
</div><p>
  Returns a copy of <code>TupleIterator1</code> where the first occurrence of a
  tuple <code>T</code> whose <code>N</code>th element compares equal to <code>Key</code> is replaced
  with <code>NewTuple</code>, if there is such a tuple <code>T</code>. If there is no such
  tuple <code>T</code>, a copy of <code>TupleIterator1</code> where <code>NewTuple</code> has been
  appended to the end is returned.</p>