old_contents: __author__ = "Tsuyoshi Hombashi"
  __copyright__ = f"Copyright 2016, {__author__}"
  __license__ = "MIT License"
  __version__ = "0.53.0"
  __maintainer__ = __author__
  __email__ = "tsuyoshi.hombashi@gmail.com"
  
new_contents: __author__ = "Tsuyoshi Hombashi"
  __copyright__ = f"Copyright 2016, {__author__}"
  __license__ = "MIT License"
  __version__ = "0.54.0"
  __maintainer__ = __author__
  __email__ = "tsuyoshi.hombashi@gmail.com"
  
subject: Bump version