old_contents: from .record import ArchiveRecord
  from .warc import WarcRecord
  from .arc import ArcRecord
  from .mixed import MixedRecord
  from .s3 import list_files
  from . import record, warc, arc
  
  def expand_files(files):
      for file in files:
          if file.startswith('s3:'):
              for f in list_files(file):
                  yield f
          else:
              yield file
  
  __all__= [
      'MixedRecord',
      'ArchiveRecord',
      'ArcRecord',
      'WarcRecord',
      'record',
      'warc',
      'arc',
      'expand_files',
  ]
  
new_contents: from .record import ArchiveRecord
  from .warc import WarcRecord
  from .arc import ArcRecord
  from .mixed import MixedRecord
  from .s3 import list_files
  from . import record, warc, arc, s3
  
  def expand_files(files):
      for file in files:
          if file.startswith('s3:'):
              for f in list_files(file):
                  yield f
          else:
              yield file
  
  __all__= [
      'MixedRecord',
      'ArchiveRecord',
      'ArcRecord',
      'WarcRecord',
      'record',
      'warc',
      'arc',
      'expand_files',
  ]
  
subject: Add s3 lib to package.