code: def oppose(value, mx):
      if value < mx / 3:
          # bottom goes up
          return mx / 3 - value + 2 * mx / 3
      elif value < 2 * mx / 3:
          # middle goes down
          return 2 * mx / 3 - value
      else:
          # top goes down
          return mx - value
  
label_desc: Use image node_id 2 for calling a global function with example usage: oppose(value, mx) and returns: unknown, unknown, unknown