code: def __init__(self, min=0, max=64 * 1024):
      """select a port number from a given range.
  
      The first call will return a random number from the available range,
      and each subsequent call will return the next number in the range.
  
      Args:
          min -- minimum port number  [default = 0]
          max -- maximum port number  [default = 65536]
      """
      self.min = min
      self.max = max
      self.first = -1
      self.current = -1
      return
  
label_desc: Use image node_id 1 to create a new portnumber object from inherited base classes: object with example: obj = portnumber(min, max)