code: def save_cout(self):
      binary_data = self.cout[self.cout_write_cursor :].encode("utf-8")
      key = s3_join(self.dir, "cout.txt")
      self.put_data(key, binary_data)
      self.cout_write_cursor = len(self.cout)
  
imports: import json
  import os
  import os.path
  from sacred.commandline_options import cli_option
  from sacred.dependencies import get_digest
  from sacred.observers.base import RunObserver
  from sacred.serializer import flatten
  import re
  import socket
label_desc: Use image node_id 15 for calling the S3Observer obj's underlying member method code with example usage: obj.save_cout() without return types