code: def firehose_alerts_bucket(config):
      """Get the bucket name to be used for historical alert retention
  
      Args:
          config (dict): The loaded config from the 'conf/' directory
  
      Returns:
          string: The bucket name to be used for historical alert retention
      """
      # The default name is <prefix>-streamalerts but can be overridden
      # The alerts firehose is not optional, so this should always return a value
      return (
          config["global"]["infrastructure"]
          .get("alerts_firehose", {})
          .get(
              "bucket_name",
              "{}-streamalerts".format(
                  config["global"]["account"]["prefix"]
              ),
          )
      )
  
imports: from collections import defaultdict, OrderedDict
  import json
  import os
  import re
  from streamalert.shared import CLUSTERED_FUNCTIONS
  from streamalert.shared.exceptions import ConfigError
  from streamalert.shared.logger import get_logger
label_desc: Use image node_id 2 for calling a global function with example usage: firehose_alerts_bucket(config) and returns: config