code: def save_contents(
      self, contents: str, fname: str, file_sub_type: FileSubtypes
  ) -> Optional[List[str]]:
      if not isinstance(self.run, wandb.sdk.wandb_run.Run):
          wandb.termwarn(
              "Not saving file contents because agent has no run"
          )
          return None
      root_dir = self.run._settings.files_dir
      saved_run_path = os.path.join(
          self.run_queue_item_id, file_sub_type, fname
      )
      local_path = os.path.join(root_dir, saved_run_path)
      os.makedirs(os.path.dirname(local_path), exist_ok=True)
      with open(local_path, "w") as f:
          f.write(contents)
      res = self.run.save(local_path, base_path=root_dir, policy="now")
      if isinstance(res, list):
          return [saved_run_path]
      else:
          wandb.termwarn(
              f"Failed to save files for run queue item: {self.run_queue_item_id}"
          )
          return None
  
imports: import os
  import sys
  from typing import List, Optional, Union
  import wandb
label_desc: Use image node_id 2 for calling the RunQueueItemFileSaver obj's underlying member method code with example usage: obj.save_contents(contents, fname, file_sub_type) and returns: None, list, None