docs: def set_line_costs(network, args, 
                     cost110=230, cost220=290, cost380=85, costDC=375):
      """ Set capital costs for extendable lines in respect to PyPSA [€/MVA]
      
      Parameters
      ----------
      network : :class:`pypsa.Network
          Overall container of PyPSA
      args: dict containing settings from appl.py
      cost110 : capital costs per km for 110kV lines and cables
                  default: 230€/MVA/km, source: costs for extra circuit in
                  dena Verteilnetzstudie, p. 146)
      cost220 : capital costs per km for 220kV lines and cables
                  default: 280€/MVA/km, source: costs for extra circuit in
                  NEP 2025, capactity from most used 220 kV lines in model
      cost380 : capital costs per km for 380kV lines and cables
                  default: 85€/MVA/km, source: costs for extra circuit in
                  NEP 2025, capactity from most used 380 kV lines in NEP
      costDC : capital costs per km for DC-lines
                  default: 375€/MVA/km, source: costs for DC transmission line 
                  in NEP 2035
      -------
  
      """
      network.lines["v_nom"] = network.lines.bus0.map(network.buses.v_nom)
  
      network.lines.loc[(network.lines.v_nom == 110),
                        'capital_cost'] = cost110 * network.lines.length /\
                            args['branch_capacity_factor']['HV']
                        
      network.lines.loc[(network.lines.v_nom == 220),
                        'capital_cost'] = cost220 * network.lines.length/\
                        args['branch_capacity_factor']['eHV']
                        
      network.lines.loc[(network.lines.v_nom == 380),
                        'capital_cost'] = cost380 * network.lines.length/\
                        args['branch_capacity_factor']['eHV']
                        
      network.links.loc[network.links.p_nom_extendable,
                        'capital_cost'] = costDC * network.links.length
  
      return network