text: import argparse
  
  # NOTE: DO NOT CHANGE ANY OF THE ARGPARSE ARGUMENTS - CHANGE NOTHING IN THIS FUNCTION
  def process_commandline():
      parser = argparse.ArgumentParser(
          description='A basic text-to-speech app that synthesises speech using diphone concatenation.')
  
      # basic synthesis arguments
      parser.add_argument('--diphones', default="./diphones",
                          help="Folder containing diphone wavs")
      parser.add_argument('--play', '-p', action="store_true", default=False,
                          help="Play the output audio")
      parser.add_argument('--outfile', '-o', action="store", dest="outfile",
                          help="Save the output audio to a file", default=None)
      parser.add_argument('phrase', nargs='?',
                          help="The phrase to be synthesised")
  
      # Arguments for extensions
      parser.add_argument('--volume', '-v', default=None, type=int,
                          help="An int between 0 and 100 representing the desired volume")
      parser.add_argument('--spell', '-s', action="store_true", default=False,
                          help="Spell the input text instead of pronouncing it normally")
      parser.add_argument('--reverse', '-r', action="store", default=None, choices=['words', 'phones', 'signal'],
                          help="Speak backwards in a mode specified by string argument: 'words', 'phones' or 'signal'")
      parser.add_argument('--fromfile', '-f', action="store", default=None,
                          help="Open file with given name and synthesise all text, which can be multiple sentences.")
      parser.add_argument('--crossfade', '-c', action="store_true", default=False,
                          help="Enable slightly smoother concatenation by cross-fading between diphone units")
  
      args = parser.parse_args()
  
      if (args.fromfile and args.phrase) or (not args.fromfile and not args.phrase):
          parser.error('Must supply either a phrase or "--fromfile" to synthesise (but not both)')
  
      return args
  