code: def _generate_graph(self, name, title, stats_data, y_name):
          
          logger.debug('Generating chart data for %s graph', name)
          orig_data, labels = self._data_dict_to_bokeh_chart_data(stats_data)
          data = self._limit_data(orig_data)
          logger.debug('Generating %s graph', name)
          script, div = FancyAreaGraph(
              name, '%s %s' % (self.project_name, title), data, labels,
              y_name).generate_graph()
          logger.debug('%s graph generated', name)
          self._graphs[name] = {
              'title': title,
              'script': script,
              'div': div,
              'raw_data': stats_data
          }
docs: Generate a downloads graph; append it to ``self._graphs``.
  
          :param name: HTML name of the graph, also used in ``self.GRAPH_KEYS``
          :type name: str
          :param title: human-readable title for the graph
          :type title: str
          :param stats_data: data dict from ``self._stats``
          :type stats_data: dict
          :param y_name: Y axis metric name
          :type y_name: str