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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 download_parallel_gui(root, urls, directory, min_file_size, max_file_size, no_redirects):
 	""" 	called when paralled downloading is true 	"""

	global parallel

	# create directory to save files
	if not os.path.exists(directory):
		os.makedirs(directory)
	parallel = True
	app = progress_class(root, urls, directory, min_file_size, max_file_size, no_redirects)