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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 bin_b64_type(arg):
 	"""An argparse type representing binary data encoded in base64."""

	try:
		arg = base64.standard_b64decode(arg)
	except (binascii.Error, TypeError):
		raise argparse.ArgumentTypeError("{0} is invalid base64 data".format(repr(arg)))
	return arg