def factory(loop_name)
      loop = @x12_definition[X12::Loop][loop_name]
      throw Exception.new("Cannot find a definition for loop #{loop_name}") unless loop
      loop = loop.dup
      return loop
    end
def factory(loop_name)
      loop = @x12_definition[X12::Loop][loop_name]
      throw Exception.new("Cannot find a definition for loop #{loop_name}") unless loop
      loop = loop.dup
      return loop
    end
parse
 Make an empty loop to be filled out with information