code: def add_timescale(self, timescale):
          
          if not isinstance(timescale, PlotTimeScale):
              self.log_exc(u"timescale must be an instance of PlotTimeScale", None, True, TypeError)
          self.timescale = timescale
          self.log(u"Added timescale")
docs: Add a time scale to the plot.
  
          :param timescale: the timescale to be added
          :type  timescale: :class:`~aeneas.plotter.PlotTimeScale`
          :raises: TypeError: if ``timescale`` is not an instance of :class:`~aeneas.plotter.PlotTimeScale`