irb
>> module RangedIndex
>>   def [] index
>>     puts "RANGED INDEX CALLED"
>>     if index.class == Range
>>       new_array = []
>>       self.keys.each{|k|new_array |= old_index(k) if index.include? k }
>>       new_array
>>     else
?>       old_index(index)
>>     end
>>   end
>>
?>   def self.extend_object(object)
>>     puts "extend called!"
>>     class << object
>>       alias_method :old_index, :[]
>> #      alias_method :[], :ranged_index
?>     end
>>   end
>> end
=> nil
>>
?> h = Hash.new
=> {}
>> h[1] = [1,2,3]
=> [1, 2, 3]
>> h.extend RangedIndex
extend called!
=> {1=>[1, 2, 3]}
>> h[1]
=> [1, 2, 3]