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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def timespan_type(arg):
 	"""An argparse type representing a timespan such as 6h for 6 hours."""

	try:
		arg = parse_timespan(arg)
	except ValueError:
		raise argparse.ArgumentTypeError("{0} is not a valid time span".format(repr(arg)))
	return arg