old_contents: __version__ = '0.1.dev0'
new_contents: #==========================================================================
  # DISTRIBUTION VERSION
  #--------------------------------------------------------------------------
  # This is a PEP 0008 and PEP 0440 compliant version string, i.e.
  # "major.minor.micro".  It is read by setup.py to determine the
  # distribution version for public release on PyPI.
  #
  # For a discussion on single-sourcing the version across setup.py and
  # the project code, see
  # https://packaging.python.org/en/latest/single_source_version.html
  #==========================================================================
  
subject: Add distribution version comments