new_contents: from tools.pypsa_io import oedb_session, get_pq_sets,\
      get_timerange, import_components, import_pq_sets, create_powerflow_problem,\
      add_coordinates, plot_line_loading
  
  from egoio.db_tables.calc_ego_hv_powerflow import Bus, Line, Generator, Load, \
      Transformer, TempResolution, GeneratorPqSet, LoadPqSet
  
  session = oedb_session()
  
  scenario = 'Status Quo'
  
  # define relevant tables of generator table
  pq_set_cols = ['temp_id', 'p_set']
  
  
  # choose temp_id
  temp_id_set = 1
  start_h = 1
  end_h = 2
  
  # examplary call of pq-set retrieval
  gen_pq_set = get_pq_sets(session, GeneratorPqSet, scenario,
                           index_col='generator_id', columns=pq_set_cols)
  load_pq_set = get_pq_sets(session, LoadPqSet, scenario, index_col='load_id',
                            columns=pq_set_cols)
  
  
  # define investigated time range
  timerange = get_timerange(session, temp_id_set, TempResolution, start_h, end_h)
  
  # define relevant tables
  tables = [Bus, Line, Generator, Load, Transformer]
  
  # get components from database tables
  components = import_components(tables, session, scenario)
  
  # create PyPSA powerflow problem
  network, snapshots = create_powerflow_problem(timerange, components)
  
  # import pq-set tables to pypsa network
  pq_object = [GeneratorPqSet, LoadPqSet]
  network = import_pq_sets(session,
                           network,
                           pq_object,
                           timerange,
                           scenario)
  
  # add coordinates to network nodes and make ready for map plotting
  network = add_coordinates(network)
  
  # start powerflow calculations
  network.pf(snapshots)
  
  # make a line loading plot
  plot_line_loading(network, output='show')
  
  
  # close session
  session.close()
subject: Add example for hv grid