text: import argparse
  
  from robot_life.field import Field
  from robot_life.running import run_field
  from robot_life.serializing_for_console import to_plaintext
  
  parser = argparse.ArgumentParser(
      prog="python3 -m robot_life",
      formatter_class=argparse.ArgumentDefaultsHelpFormatter,
  )
  # the width of terminal VT100 by default
  parser.add_argument("-W", "--width", type=int, default=80, help="field width")
  # the height of terminal VT100 by default
  parser.add_argument("-H", "--height", type=int, default=24, help="field height")
  parser.add_argument("-P", "--period",
      type=float, default=0.1, help="population period")
  parser.add_argument("-C", "--capacity",
      type=float, default=1_000_000, help="maximal history capacity")
  parser.add_argument("-V", "--variants",
      default=".:*#O", help="character variants")
  
  args = parser.parse_args()
  
  field = Field(args.width, args.height, Field.random_generator)
  run_field(
      field=field,
      handler=lambda field_history: \
          print(to_plaintext(field_history, args.variants)),
      population_period=args.period,
      maximal_history_capacity=args.capacity,
  )
  