code: def gisland(self, dae):
          
          if (not self.islanded_buses) and (not self.island_sets):
              return
  
          a, v = list(), list()
  
          # for islanded areas without a slack bus
          # TODO: fix for islanded sets without sw
          # for island in self.island_sets:
          #     nosw = 1
          #     for item in self.system.SW.bus:
          #         if self.uid[item] in island:
          #             nosw = 0
          #             break
          #     if nosw:
          #         self.islanded_buses += island
          #         self.island_sets.remove(island)
  
          a = self.islanded_buses
          v = [self.n + item for item in a]
          dae.g[a] = 0
          dae.g[v] = 0
docs: Reset g(x) for islanded buses and areas