old_contents: from version import __version__
  from commandify import CommandifyArgumentParser, CommandifyError
  from commandify import commandify, command, main_command
  from commandify import _commands, _main_commands
  
new_contents: from version import __version__
  from commandify import CommandifyArgumentParser, CommandifyError
  from commandify import commandify, command, main_command
  from commandify import _commands, _main_commands
  
  __all__ = [
      '__version__',
      'CommandifyArgumentParser',
      'CommandifyError',
      'commandify',
      'command',
      'main_command',
      '_commands',
      '_main_commands'
  ]
  
subject: Add __all__ to __init__ for import *.