docs: def sec_overview(self):
          """
          Generate the data for the Overview section in the report
          :return:
          """
  
          """ Data sources overview: table with metric summaries"""
          metrics = self.config['overview']['activity_metrics']
          file_name = self.config['overview']['activity_file_csv']
  
          data_path = os.path.join(self.data_dir, "data")
          file_name = os.path.join(data_path, file_name)
  
          logger.debug("CSV file %s generation in progress", file_name)
  
          csv = 'metricsnames,netvalues,relativevalues,datasource\n'
          for metric in metrics:
              # comparing current metric month count with previous month
              es_index = self.get_metric_index(metric)
              ds = metric.ds.name
              m = metric(self.es_url, es_index, start=self.start, end=self.end)
              (last, percentage) = m.get_trend()
              csv += "%s,%i,%i,%s" % (metric.name, last, percentage, ds)
              csv += "\n"
          os.makedirs(os.path.dirname(file_name), exist_ok=True)
          with open(file_name, "w") as f:
              # Hack, we need to fix LaTeX escaping in a central place
              csv = csv.replace("_", r"\_")
              f.write(csv)
  
          logger.debug("CSV file: %s was generated", file_name)
  
          """
          Git Authors:
  
          description: average number of developers per month by quarters
          (so we have the average number of developers per month during
          those three months). If the approach is to work at the level of month,
          then just the number of developers per month.
          """
  
          author = self.config['overview']['author_metrics'][0]
          csv_labels = 'labels,' + author.id
          file_label = author.ds.name + "_" + author.id
          title_label = author.name + " per " + self.interval
          self.__create_csv_eps(author, None, csv_labels, file_label, title_label)
  
          logger.debug("CSV file %s generation in progress", file_name)
  
          bmi = []
          ttc = []  # time to close
  
          csv_labels = ''
          for m in self.config['overview']['bmi_metrics']:
              metric = m(self.es_url, self.get_metric_index(m),
                         start=self.end_prev_month, end=self.end)
              csv_labels += m.id + ","
              bmi.append(metric.get_agg())
  
          for m in self.config['overview']['time_to_close_metrics']:
              metric = m(self.es_url, self.get_metric_index(m),
                         start=self.end_prev_month, end=self.end)
              csv_labels += m.id + ","
              ttc.append(metric.get_agg())
  
          csv = csv_labels[:-1] + "\n"  # remove last comma
          csv = csv.replace("_", "")
          for val in bmi:
              csv += "%s," % (self.str_val(val))
          for val in ttc:
              csv += "%s," % (self.str_val(val))
          if csv[-1] == ',':
              csv = csv[:-1]
  
          data_path = os.path.join(self.data_dir, "data")
          file_name = os.path.join(data_path, 'efficiency.csv')
          os.makedirs(os.path.dirname(file_name), exist_ok=True)
          with open(file_name, "w") as f:
              f.write(csv)
  
          logger.debug("CSV file: %s was generated", file_name)