code: def graph(self, graphing_library='matplotlib'):
      
      logger.info('Using graphing_library {lib} for metric {name}'.format(lib=graphing_library, name=self.label))
      self.plot_cdf(graphing_library)
      self.plot_timeseries(graphing_library)
      return True
docs: graph generates two types of graphs
      'time': generate a time-series plot for all submetrics (the x-axis is a time series)
      'cdf': generate a CDF plot for important submetrics (the x-axis shows percentiles)