class_docstr: Trainer based on (R)ecorder and Task(M)anager.
  It can train a list of tasks and return a list of model recorders in a multiprocessing way.
  
  Assumption: `task` will be saved to TaskManager and `task` will be fetched and trained from TaskManager
class_docstr_tok: ["Trainer","based","on","(","R",")","ecorder","and","Task","(","M",")","anager",".","It","can","train","a","list","of","tasks","and","return","a","list","of","model","recorders","in","a","multiprocessing","way",".","Assumption",":","`","task","`","will","be","saved","to","TaskManager","and","`","task","`","will","be","fetched","and","trained","from","TaskManager"]
docstr: Set STATUS_END tag to the recorders.
  
  Args:
      recs (list): a list of trained recorders.
  
  Returns:
      List[Recorder]: the same list as the param.
docstr_tok: ["Set","STATUS_END","tag","to","the","recorders",".","Args",":","recs","(","list",")",":","a","list","of","trained","recorders",".","Returns",":","List","[","Recorder","]",":","the","same","list","as","the","param","."]
code: def end_train(self, recs: list, **kwargs) -> List[Recorder]:
      """
      Set STATUS_END tag to the recorders.
  
      Args:
          recs (list): a list of trained recorders.
  
      Returns:
          List[Recorder]: the same list as the param.
      """
      if isinstance(recs, Recorder):
          recs = [recs]
      for rec in recs:
          rec.set_tags(**{self.STATUS_KEY: self.STATUS_END})
      return recs
  
imports: import socket
  from typing import Callable, List, Optional
  from tqdm.auto import tqdm
  from qlib.config import C
  from qlib.data.dataset import Dataset
  from qlib.data.dataset.weight import Reweighter
  from qlib.log import get_module_logger
  from qlib.model.base import Model
  from qlib.utils import auto_filter_kwargs, fill_placeholder, flatten_dict, init_instance_by_config
  from qlib.utils.paral import call_in_subproc
  from qlib.workflow import R
  from qlib.workflow.recorder import Recorder
  from qlib.workflow.task.manage import TaskManager, run_task
label_desc: Use image node_id 3 for calling the TrainerRM obj's underlying member method code with example usage: obj.end_train(recs) and returns: recs