new_contents: #!python3
  
  import os
  
  from PIL import Image, ImageDraw, ImageFont
  
  BLANK_FLAG = Image.open(
      os.path.join(os.path.dirname(__file__), "dont-tread-on-blank.png")
  )
  
  
  def tread_on(phrase):
      """Caption the "Don't Tread on Me" snake with `phrase`"""
      flag = BLANK_FLAG.copy()
      draw = ImageDraw.Draw(flag)
      font = ImageFont.truetype("Times New Roman", 120)
  
      text = "Don't {} me".format(phrase)
      font_pos = (flag.width / 2 - font.getsize(text)[0] / 2, 1088)
  
      draw.text(font_pos, text, font=font, fill="black")
  
      return flag
  
subject: Add main program