docs: def _padding_model_number(number, max_num):
      '''
      This method returns a zero-front padded string
  
      It makes out of str(45) -> '0045' if 999 < max_num < 10000. This is
      meant to work for reasonable integers (maybe less than 10^6).
  
      Parameters
      ----------
      number : integer
          number that the string should represent.
      max_num : integer
          max number of cycle list, implies how many 0s have be padded
  
      '''
  
      cnum = str(number)
      clen = len(cnum)
  
      cmax = int(log10(max_num)) + 1
  
      return (cmax - clen)*'0' + cnum