code: def good_port_ranges(ports=None, min_range_len=20, border=3):
      
      min_range_len += border*2
      if ports is None:
          ports = available_ports()
      ranges = utils.to_ranges(list(ports))
      lenghts = sorted([(r[1]-r[0], r) for r in ranges], reverse=True)
      long_ranges = [l[1] for l in lenghts if l[0] >= min_range_len]
      without_borders = [(low+border, high-border) for low, high in long_ranges]
      return without_borders
docs: Returns a list of 'good' port ranges.
      Such ranges are large and don't contain ephemeral or well-known ports.
      Ranges borders are also excluded.