code: def set_branch_ids(self):
          
  
          # MV grid:
          ctr = 1
          for branch in self.graph_edges():
              branch['branch'].id_db = self.grid_district.id_db * 10**4 + ctr
              ctr += 1
  
          # LV grid:
          for lv_load_area in self.grid_district.lv_load_areas():
              for lv_grid_district in lv_load_area.lv_grid_districts():
                  ctr = 1
                  for branch in lv_grid_district.lv_grid.graph_edges():
                      branch['branch'].id_db = lv_grid_district.id_db * 10**7 + ctr
                      ctr += 1
docs: Generates and sets ids of branches for MV and underlying LV grids.
          
          While IDs of imported objects can be derived from dataset's ID, branches
          are created within DING0 and need unique IDs (e.g. for PF calculation).