old_contents: import os.path
  
  from pkg_resources import get_distribution, DistributionNotFound
  
  from .filter import ifilter, ifilterfalse, takewhile, dropwhile
  from .grouping import groupby
  from .iter_dispatch import (
      _iter, ordered_sequence_iterator, file_iterator, range_iterator
  )
  from .map_zip import imap, starmap, izip, izip_longest
  from .permutations import (
      permutations, combinations, combinations_with_replacement
  )
  from .product import product
  from .simple import accumulate, chain, compress, count, cycle, repeat
  from .slicing import islice
  from .tee import tee
  
  # Python 3 equivalents.
  filter = ifilter
  filterfalse = ifilterfalse
  zip = izip
  zip_longest = izip_longest
  
  
  try:
      DIST = get_distribution('picklable_itertools')
      DIST_LOC = os.path.normcase(DIST.location)
      HERE = os.path.normcase(__file__)
      if not HERE.startswith(os.path.join(DIST_LOC, 'picklable_itertools')):
          raise DistributionNotFound
  except DistributionNotFound:
      __version__ = 'not installed'
  else:
      __version__ = DIST.version
  
  
  __all__ = ['ifilter', 'ifilterfalse', 'takewhile', 'dropwhile', 'groupby',
             '_iter', 'ordered_sequence_iterator', 'file_iterator',
             'range_iterator', 'imap', 'starmap', 'izip', 'izip_longest',
             'permutations', 'combinations', 'combinations_with_replacement',
             'accumulate', 'chain', 'compress', 'count', 'cycle', 'repeat',
             'islice', 'tee']
  
new_contents: import os.path
  
  from pkg_resources import get_distribution, DistributionNotFound
  
  from .filter import ifilter, ifilterfalse, takewhile, dropwhile
  from .grouping import groupby
  from .iter_dispatch import (
      _iter, ordered_sequence_iterator, file_iterator, range_iterator
  )
  from .map_zip import imap, starmap, izip, izip_longest
  from .permutations import (
      permutations, combinations, combinations_with_replacement
  )
  from .product import product
  from .simple import accumulate, chain, compress, count, cycle, repeat
  from .slicing import islice
  from .tee import tee
  
  # Python 3 equivalents.
  filter = ifilter
  filterfalse = ifilterfalse
  zip = izip
  zip_longest = izip_longest
  
  
  try:
      DIST = get_distribution('picklable_itertools')
      DIST_LOC = os.path.normcase(DIST.location)
      HERE = os.path.normcase(__file__)
      if not HERE.startswith(os.path.join(DIST_LOC, 'picklable_itertools')):
          raise DistributionNotFound
  except DistributionNotFound:
      __version__ = 'not installed'
  else:
      __version__ = DIST.version
  
  
  __all__ = ['ifilter', 'ifilterfalse', 'takewhile', 'dropwhile', 'groupby',
             '_iter', 'ordered_sequence_iterator', 'file_iterator',
             'range_iterator', 'imap', 'starmap', 'izip', 'izip_longest',
             'permutations', 'combinations', 'combinations_with_replacement',
             'accumulate', 'chain', 'compress', 'count', 'cycle', 'repeat',
             'islice', 'tee', 'filter', 'filterfalse', 'zip', 'zip_longest']
  
subject: Add equivalents to `__all__`.