old_contents: """Declare basic string types unambiguously for various Python versions.
  
  Authors
  -------
  * MinRK
  """
  
  #
  #    Copyright (c) 2010 Min Ragan-Kelley, Brian Granger
  #
  #    This file is part of pyzmq.
  #
  #    pyzmq is free software; you can redistribute it and/or modify it under
  #    the terms of the Lesser GNU General Public License as published by
  #    the Free Software Foundation; either version 3 of the License, or
  #    (at your option) any later version.
  #
  #    pyzmq is distributed in the hope that it will be useful,
  #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  #    Lesser GNU General Public License for more details.
  #
  #    You should have received a copy of the Lesser GNU General Public License
  #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  #
  
  import sys
  
  major,mior = sys.version_info[:2]
  if major >= 3:
      bytes = bytes
      unicode = str
      basestring = (bytes, unicode)
      asbytes = lambda s: s if isinstance(s, bytes) else unicode(s).encode('utf8')
  
  elif major == 2:
      unicode = unicode
      bytes = str
      basestring = basestring
      asbytes = str
  
  __all__ = ['asbytes', 'bytes', 'unicode', 'basestring']
  
new_contents: """Declare basic string types unambiguously for various Python versions.
  
  Authors
  -------
  * MinRK
  """
  
  #
  #    Copyright (c) 2010 Min Ragan-Kelley, Brian Granger
  #
  #    This file is part of pyzmq.
  #
  #    pyzmq is free software; you can redistribute it and/or modify it under
  #    the terms of the Lesser GNU General Public License as published by
  #    the Free Software Foundation; either version 3 of the License, or
  #    (at your option) any later version.
  #
  #    pyzmq is distributed in the hope that it will be useful,
  #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  #    Lesser GNU General Public License for more details.
  #
  #    You should have received a copy of the Lesser GNU General Public License
  #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  #
  
  import sys
  
  major,mior = sys.version_info[:2]
  if major >= 3:
      bytes = bytes
      unicode = str
      basestring = (bytes, unicode)
      asbytes = lambda s: s if isinstance(s, bytes) else unicode(s).encode('utf8')
  
  elif major == 2:
      unicode = unicode
      bytes = str
      basestring = basestring
      asbytes = str
  
  # give short 'b' alias for asbytes, so that we can use fake b('stuff')
  # to simulate b'stuff'
  b = asbytes
  
  __all__ = ['asbytes', 'bytes', 'unicode', 'basestring', 'b']
  
subject: add 'b' alias to as bytes for 2.5-style bytes-literals