code: def _objects_exist_in_dir(self, prefix):
      # This should be run after you've confirmed the bucket
      # exists, and will error out if it does not exist
  
      bucket = self.s3.Bucket(self.bucket)
      all_keys = [el.key for el in bucket.objects.filter(Prefix=prefix)]
      return len(all_keys) > 0
  
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 2 for calling the S3Observer obj's underlying member method code with example usage: obj._objects_exist_in_dir(prefix) and returns: unknown