code: def push_line(self, tokens):
          
          logger.debug("Pushing line data: %s" % tokens)
  
          from_bus = self.case.buses[tokens["fbus"]-1]
          to_bus = self.case.buses[tokens["tbus"]-1]
  
          e = Branch(from_bus=from_bus, to_bus=to_bus)
          e.r = tokens["r"]
          e.x = tokens["x"]
          e.b = tokens["b"]
          e.rate_a = tokens["s_limit"]
          e.rate_b = tokens["p_limit"]
          e.rate_c = tokens["i_limit"]
          # Optional parameter
          if tokens["tap"] == 0: #Transmission line
              e.ratio = 1.0
          else: # Transformer
              e.ratio = tokens["tap"]
          e.phase_shift = tokens["shift"]
          # Optional parameter
  #        if "status" in tokens.keys:
  #        e.online = tokens["status"]
  
          self.case.branches.append(e)
docs: Adds a Branch object to the case.