code: def _get_prefix_from_bucket_config(self, config):
      scheme = "s3"
      prefix = furl.furl()
  
      if config.host:
          prefix.set(
              scheme=scheme,
              netloc=config.host.lower(),
              path=config.bucket.lower() if config.bucket else "",
          )
      else:
          prefix.set(scheme=scheme, path=config.bucket.lower())
          bucket = prefix.path.segments[0]
          prefix.path.segments.pop(0)
          prefix.set(netloc=bucket)
  
      return str(prefix)
  
imports: import abc
  import warnings
  from copy import copy
  from operator import itemgetter
  from os import getenv
  import furl
  import six
  from attr import attrib, attrs
label_desc: Use image node_id 7 for calling the S3BucketConfigurations obj's underlying member method code with example usage: obj._get_prefix_from_bucket_config(config) and returns: str