code: def _add_ps2q(self, throat, queue):
          
          net = self.project.network
          elem_type = 'pore'
          # Find pores connected to newly invaded throat
          Ps = net['throat.conns'][throat]
          # Remove already invaded pores from Ps
          Ps = Ps[self['pore.invasion_sequence'][Ps] <= 0]
          if len(Ps) > 0:
              self._interface_Ps[Ps] = True
              for P in Ps:
                  data = []
                  # Pc
                  data.append(self["pore.entry_pressure"][P])
                  # Element Index
                  data.append(P)
                  # Element Type (Pore of Throat)
                  data.append(elem_type)
                  hq.heappush(queue, data)
docs: Helper method to add pores to the cluster queue