code: def _is_valid_bucket(bucket_name):
      # See https://docs.aws.amazon.com/awscloudtrail/latest/userguide/
      # cloudtrail-s3-bucket-naming-requirements.html
      if len(bucket_name) < 3 or len(bucket_name) > 63:
          return False
  
      labels = bucket_name.split(".")
      # A bucket name consists of "labels" separated by periods
      for label in labels:
          if len(label) == 0 or label[0] == "-" or label[-1] == "-":
              # Labels must be of nonzero length,
              # and cannot begin or end with a hyphen
              return False
          for char in label:
              # Labels can only contain digits, lowercase letters, or hyphens.
              # Anything else will fail here
              if not (char.isdigit() or char.islower() or char == "-"):
                  return False
      try:
          # If a name is a valid IP address, it cannot be a bucket name
          socket.inet_aton(bucket_name)
      except socket.error:
          return True
  
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 1 for calling a global function with example usage: _is_valid_bucket(bucket_name) and returns: False, False, True, False