docs: def max_line_ext(network, snapshots, share=1.01):
  
      """
      Sets maximal share of overall network extension
      as extra functionality in LOPF
  
      Parameters
      ----------
      share: float
          Maximal share of network extension in p.u.
      """
  
      lines_snom = network.lines.s_nom.sum()
      links_pnom = network.links.p_nom.sum()
  
      def _rule(m):
  
          lines_opt = sum(m.passive_branch_s_nom[index]
                          for index
                          in m.passive_branch_s_nom_index)
  
          links_opt = sum(m.link_p_nom[index]
                          for index
                          in m.link_p_nom_index)
  
          return (lines_opt + links_opt) <= (lines_snom + links_pnom) * share
      network.model.max_line_ext = Constraint(rule=_rule)