code: def _first_stage_act(self):
      self._calc_sub_topo_dict()
  
      action = self._check_serial_actions()
      if action is not None:
          return action
  
      action = self._reconnect_action()
      if action is not None:
          return action
  
      if np.all(self.observation.topo_vect != -1):
          self.used_combine_actions = False
          self.redispatch_cnt = 0
  
      if self.observation is not None and not any(
          np.isnan(self.observation.rho)
      ):
          if np.all(self.observation.topo_vect != -1):
              action = self._reset_redispatch()
              if action is not None:
                  return action
  
              action = self._reset_topology()
              if action is not None:
                  return action
  
      (
          obs_simulate,
          reward_simulate,
          done_simulate,
          info_simulate,
      ) = self.observation.simulate(self.do_nothing_action)
      self.observation._obs_env._reset_to_orig_state()
  
      has_overflow = False
      if self.observation is not None and not any(
          np.isnan(self.observation.rho)
      ):
          has_overflow = any(self.observation.rho > 1.0)
  
      if done_simulate or has_overflow:
          if (
              self.observation.line_status[56] == False
              or self.observation.line_status[45] == False
          ) and not self.used_combine_actions:
              action = self._three_sub_action()
              if action is not None:
                  return action
  
          action = self._unitary_actions_simulate()
          if action is not None:
              return action
  
      return self.do_nothing_action
  
imports: import torch
  import numpy
  import pickle
  import os
  from grid2op.Agent import BaseAgent
  from copy import deepcopy
  from powernet_model import CombinedActionModel, UnitaryActionModel
  from utils import FeatureProcessor, UnitaryFeatureProcessor
label_desc: Use image node_id 6 for calling the RLAgent obj's underlying member method code with example usage: obj._first_stage_act() and returns: self, action, action, action, action, action, action