docs: def compact_tables(self):
          """
          Compact report items of type "table" with same results type. Report items of type "tables" in the
          same subreport is merged into one. The data are ordered by 1st column.
          """
          items_to_del = set()
          for i in range(len(self.report_data)):
              if i in items_to_del:
                  continue
              if self.report_data[i].function[0:5] == 'table':
                  for j in range(i+1, len(self.report_data)):
                      if self.report_data[j].function[0:5] == 'table':
                          if self.report_data[i] == self.report_data[j]:
                              logger.debug('Merge of 2 identical report tables: {0}'
                                           .format(self.report_data[i].title)) 
                              items_to_del.add(j)
                              self.report_data[i].results.extend(self.report_data[j].results)
          if items_to_del:
              for i in reversed(sorted(items_to_del, key=lambda x: x)):
                  self.report_data.pop(i)