code: def show_time_as_short_string(self, seconds):
          
          if seconds < 60:
              return str(seconds) + ' seconds'
          elif seconds < 3600:
              return str(round(seconds/60, 1)) + ' minutes'
          elif seconds < 3600*24:
              return str(round(seconds/(60*24), 1)) + ' hours'
          elif seconds < 3600*24*365:
              return str(round(seconds/(3600*24), 1)) + ' days'
          else:
              print('WARNING - this will take ' + str(seconds/(60*24*365)) + ' YEARS to run' )
              return str(round(seconds/(60*24*365), 1)) + ' years'
docs: converts seconds to a string in terms of 
          seconds -> years to show complexity of algorithm