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Technical Overview
  internal package Foswiki::Iterator::NumberRangeIterator  is a Foswiki::Iterator 
Iterator over a range of integer values, with programmable increment.
 ClassMethod new($start, $end, $inc) 
Construct a new iterator from start to end step inc.
The range is inclusive i.e. if $end == $start, you will get an iterator
that returns a single value.
The iteration step is the absolute value of $inc, and defaults to 1.