old_contents: # single source of truth for package version,
  # see https://packaging.python.org/en/latest/single_source_version/
  __version__ = "1.5.0"
  
new_contents: # single source of truth for package version,
  # see https://packaging.python.org/en/latest/single_source_version/
  __version__ = "1.6.0"
  
subject: Update to v1.6.0